Recently there was a schism on the internet between people about the color of a dress.  That led to all kinds of scientific articles about how we perceive color differently, memes about white and gold things and black and blue things, and finally, eventually, this.

Screen Shot 2015-03-02 at 4.13.41 PM

That is from an article on LinkedIn, written by a woman named Diana Derval, who claims to be an expert in neuromarketing, whatever the fuck that is.  The title of the article looks like this:

Nothing says legitimate scientific knowledge like a winky face with its tongue out.
Nothing says legitimate scientific knowledge like a winky face with its tongue out.

This is already almost a hundred percent incorrect, but in order to explain why, I need to give you a little anatomy lesson.

Vision starts in the eye.  There are three sets of cells in the eye called “cones” and one set called “rods.”  Rods only have one kind of light-sensitive pigment in them, which means they can only tell how much light is coming in, not what color it is.  They are far more sensitive than cone cells and are almost entirely responsible for low-light vision, but have little to no role in color vision.

The majority of people have three cones, called L, M, and S for the long-, medium-, and short-wavelength light they detect.  After the pigments pick up light, they are sent to the brain along three channels, one for each color.  L corresponds with red, M with green, and S with blue.

Roughly one in sixteen men is what’s called red-green colorblind, which is a slightly misleading term.  The correct term is anomalous trichromacy, meaning they have two fully functioning sets of cone cells instead of three.  The S (blue) set is fine, but either the M (green) has sensitivity shifted toward the red portion of the spectrum, or the L (red) has shifted toward the green.  Importantly, though, the brain does not know that this has happened.  This is a genetic condition that affects the eyes, but not the color-sensing portion of the brain.  The brain assumes that each cone is sending it the correct color and builds images accordingly.

I, for example, am deuteranomalous.  I have a perfectly functional set of S cones and a perfectly functional set of L cones, but my M cones are shifted toward the L end of the spectrum.  This means, theoretically, that I am less sensitive to green light than a person with normal vision, but I can’t tell.  As far as my brain is concerned, the signals are coming through fine.

Here’s an example.  Imagine a gray square, composed of equal parts blue, red, and green light.  Then you turn up the red and blue light, making the gray square a sort of dull magenta color.  To you, that square is now magenta. My stupid deformed M cones, however, are detecting red when they shouldn’t be, so they detect the increase in red light as well.  They report back to the brain that the green levels have gone up, when they haven’t. My brain is now getting signals that all three channels of light have increased in magnitude and the square is now a brighter shade of gray.  It’s not.  It’s pink.  But I can’t tell.  Want to see that in action?

Screen Shot 2015-03-02 at 5.04.32 PM

This is a graphic to test my particular flavor of color blindness.  My coworker assures me that the sky inside the circle is pink, but I can’t tell because my dumbfuck M cells think that the increase in red and blue is an increase in all three colors, which cancels out.  I can tell that it’s not exactly the same as the other sky, but it’s more of a texture than a color.  She tells me that the grass in the circle is yellower (because red light was added to the existing green), but I can’t tell for the same reason.  The gist of it is that if something is pure green, it looks paler to me.  If you add red to something, I can’t tell.  Dark blue and purple are a nightmare. Traffic lights look very pale, almost blue.  Dull greens look brown because I can’t see the green part.  And so on.

This brings me back around to tetrachromacy, or the presence of four sets of cone cells.  A Dutch researcher in the 1940s noticed that the mothers and daughters of deuteranomalous men like myself all had normal color vision.  He knew that the genes responsible for cone cells came from sex chromosomes, which left two possible explanations.  If the mutated M cells came exclusively from the father, all fathers and sons of deuteranomalous men would have the same condition, which wasn’t the case.  If they came in equal part from the mother, then deuteranomaly would be similarly present in women, which wasn’t the case.  He concluded, therefore, that the mothers and daughters of deuteranomalous men must have a fourth set of cells, giving them three functional ones and one mutant.  He hypothesized that women with four functional sets of cells might exist, but it wasn’t the point of his research so he didn’t look into it.

This has been a long wall of text. Here is a cat being friends with a horse.

Fast forward to 1980, when two researchers became intrigued by the idea of four-coned women.  They knew that anomalous trichromacy was common, which meant that four-coned women must be common as well.  They sought out the mothers and daughters of colorblind men and had them take a color matching test.  In such a test, the subject mixes levels of red and green light to match the yellow light provided.  Colorblind men will have to add more of either red or green to compensate for their defective cones, and people with normal vision will be able to match the colors correctly.  People with four cones, theoretically, would be able to tell the difference between true yellow light and light made by mixing red and green, and would therefore be unable to make a match.  That wasn’t the case.  The researchers found plenty of women with four sets of cones, but none of them had more sensitive color vision than the average trichromat.

In 2007, one of the researchers tried a different technique.  She flashed three colored circles in front of her subjects’ eyes.  A trichromat would have been unable to tell them apart, but a tetrachromat should have been able to recognize that one of the circles was actually a very subtle mix of red and green, rather than a solid yellow color.  Only one woman was able to pass the test.  Which brings me to my point (1100 words later):

If two researchers who dedicated their careers to the task were only able to find one functional tetrachromat in 27 years, do you really think that a test on LinkedIn written by a marketing professor is going to help?

Obviously, the answer is no.  But there’s more bullshit here.  First, the title.

25% of people are tetrachromats

Lies.  It’s something like 12% of women, which is 6% of people — and is probably more common in women of Northern European ancestry, so that number’s even lower worldwide — and it’s so rare that women with four cells can actually use them that we can’t even put a number to it.  Only two women in history have ever been empirically confirmed as functional tetrachromats.

and see colors as they are

That’s a preposterous thing to say.  Everyone’s cones see slightly differently already due to genetic variation, so theoretically the same wavelength of light looks infinitesimally different to every single person.  The only reason color blindness is a thing is that color blind people can’t distinguish between certain colors, not that they’re seeing them wrong.  Sure, you can empirically say that a certain LED bulb emits light at a wavelength of 581nm, but what does that look like?  No one can really say for sure.  There is no such thing as colors “as they are.”

You see less than 20 color nuances: you are a dichromats, like dogs, which means you have 2 types of cones only. You are likely to wear black, beige, and blue. 25% of the population is dichromat.

Horseshit.  Dichromacy affects less than 3% of males and .03% of women.  That’s about 1.5% of the general population.

You see between 33 and 39 colors: you are a tetrachromat, like bees

No part of that is true.  Firstly, you can’t diagnose tetrachromacy on a computer screen AT ALL because computer screens are made up of combinations of only three different colors of light.  It is literally not possible for an LED computer screen to generate the kind of nuance that distinguishes tetrachromats from trichromats.  Secondly, bees see in ultraviolet, meaning their extra color vision is in a wavelength that no human being (or even mammal)* has ever seen.  Being a tetrachromat in the visible spectrum does not mean you can see what bees see.  And thirdly, BEES ARE NOT TETRACHROMATS. Bees are trichromats, with cones in what we might call the green-yellow, blue, and UV portions of the spectrum.  They still only have three cones.

It is highly probable that people who have an additional 4th cone do not get tricked by blue/black or white/gold dresses, no matter the background light

Die in a multicolored fire.  Let me say this one more time: that dress is a photo on a computer screen, taken on a digital camera.  The screen on your computer is only capable of generating three wavelengths of light, and all others are projected as mixtures of those three.  The sensor in your camera only records three wavelengths of light (because that’s what you see in), and all others are a mixture of those three.  ANY COLOR IN THE WORLD THAT IS NOT A SPECIFIC WAVELENGTH OF RED, GREEN, OR BLUE is shoehorned into a combination of those three by your eyes, your brain, your camera, and your screen.

This graphic is like testing your depth perception with one eye closed***.  It is fundamentally impossible.  It is stupid, insulting, and worst of all, it is popular.  Stop it immediately.

*[EDIT 03/10: Turns out a whole shitload of mammals can see in UV, but humans are not among them.]**
**[EDIT OF THE EDIT 03/12: Turns out that some humans can see in UV (a condition called aphakia) some of the time.  UV is blocked by the lens, so if the lens is fucked up due to surgical removal, a perforating wound or ulcer, or congenital anomaly, UV light can hit the retina.  It is thought that Claude Monet was aphakic because he painted flowers in a way that a person with normal vision shouldn’t have been able to see.]
***[EDIT 03/12: It is possible to percieve depth to a small extent with one eye based on perspective, size comparison, motion, and the flexing of the lens in the eye to adjust focal length.  TESTING depth perception using one eye would still be dumb.]

172 Thoughts

  1. Thank you for that great article. For I’m a real tetrachromat, I have hours of discussing about colors of dresses, pictures, walls, flowers, an so on. And some of the persons I talked with, think they’re tetrachromats too, because of counting that stupid, compressed pixels, though they can’t divide yellow from orange -.- Great, great thanks!

    1. Some people with only 3 types of cones can tell the difference between some colors that look exactly the same as each other to other people because they work with them on a regular basis, so unless you have gone to a doctor and asked them, you just might have the normal amount of cones.

      1. So to answer the question “is it theoretically possible?” I would say yes, but extremely unlikely, at least to be a tetrachromat in the sense of a genetically inherited trait.

      2. this is not impossible , but Men aren’t as likely to be tetrachromats .
        as like as xx male called De la Chapelle syndrome or xxy male called Klinefelter syndrome

      3. hello
        ths is not genetically impossible , but it’s almost impossible.
        because a few men have two x chromosomes ( xx or xxy)

  2. I couldn’t stop laughing at “Die in a multicolored fire” that was the best part of the article so far!! hahaha. I really liked this article, you made it easy and interesting, good job.

  3. If we’re just going by number of cone variations, the odds that a female carrier would *not* be a tetrachromat are pretty low. Which one of the inherited X chromosomes is expressed in a particular cell is determined by what amounts to a coin flip, so the retinas of a carrier would be a mosaic of normal-L, normal-M, normal-S, and mutant-M/L, depending on whether she carried protanomaly or deuteranomaly. Chances of zero cells in either eye expressing the mutant chromosome instead of the normal one are really not that good.

    Whether this is of any practical value is another matter. Red-green colorblindness runs on my mother’s side of the family, and my eyes have subtly different white balances, so unless something truly new and bizarre has happened, I must be a carrier, and each eye must’ve gotten a slightly different ratio of mutant to normal cones. The mutant cones don’t respond to any wavelengths outside the normal gamut, they just respond differently to the same ol’ wavelengths everything else gets; if there’s any practical value in it, it’s probably that I’ve learned to notice when I’ve got a slightly different signal coming in from each eye, and discriminate between colors in the overlap area based on the contrast.

    I am one of those irritating people who can correctly name eleventy-nine colors and thinks there are different shades of black and white, but this is mostly because I’m observant, I practice, and I care. And I can’t do it on a poorly-compressed JPEG.

    (I am definitely keeping the link to this article around; you have one of the clearest explanations of why all the stuff in the red-green area of color blends into one smooth gradient of gred for you, and why you deem odd bits of it ‘gray’ instead.)

    1. My eyes have diffrent white balances too, (one more yellow/warmer, one more blue/colder) and so does my co-workers/best friends.
      As far as I know red-green blindness doesn’t run in either of our families.
      I always assumed the slight diffrence in white balance in each eye was normal and something everyone had. It probably balances out to a normal color representation as long as you have two functioning healthy eyes anyway since the white balances seem to cancel each other out..

      It’s just something you’re not likely to pay too much attention to unless you’re A: a bored kid on a long car ride B: Someone who works with their eyes extensively like an illustrator or graphic designer.

      In my case I grew from the former into the latter.

      I also have very slight short-sightedness, wich is worse in one eye, so for a while I did loads of quick switches between the two to determine if one of my eyes was really worse than the other, before going to an optician.

  4. I wish that I could know for sure if I’m a tetrachromat. I just took the online color test, and i got the score: 0 (which is a good thing), I have also completed all of the puzzles in blenduko 2 (with a time below the world average on all of them) and i have a score on 100 in their color IQ test. But I don’t know for sure though. Is there any way I can find out?

    1. Not on a computer screen, no matter what the venue. To find out if you’re a functional tetrachromat, you’d need to compare yellow light that’s truly yellow—something computers can’t possibly produce—and yellow light that’s a mixture of red and green. That probably means xenon bulbs and specific gels, or maybe carefully calibrated printing, I’m not sure of the actual experimental process. But I can save you some time and tell you with near-absolute certainty that you’re not a (functional) tetrachromat. Almost no one is, to the point that it took thirty years of study to even confirm that such a thing was possible.

      1. They gave me a colour test like this when I was younger because my eye doctor suggested it to see if I was colour blind. When I was younger my mother would mix paint for her hobbyist paintings. I (apparently) asked on multiple occasions what she called the colours. She would reply with like Purple and I’d start an argument that it wasn’t purple. That it was something else. (Can you imagine me rolling my eyes at this point? I got put in time out more than once for having this argument with my mum.) Eventually, it snowballed into this fear that I was colour blind. (I had also freaked her out by coming out with white hair and pasty white skin. She assumed I was albino. My mother is a freak. I’m not albino. I was just pasty all my childhood because the outdoors sucked. I wanted to read more than play outside. It happens.)

        I digress. Well, the eye doctor did a colour test on me. I got to sit in a box and had colours flashed on a wall and I had to identify them. At one point, he flashed a colour and I said I didn’t know. So he showed me again and asked me to describe it. He was testing for red deficiency I think or something. But It was a mix of green and red or whatnot. (It’s been about 20 years at this point.)

        All in all, he suggested to my mother that I might be something like Tetrachromatic. Because I was picking up subtle changes in hues of light that (apparently) should not have been possible for seven or eight year old me.

        I don’t know for sure even now. My crazy as a bat mother told all her friends her daughter could see more colours than the average person. And I died of embarrassment every time. I didn’t even think about it after I became an adult and this stupid gradient test was showing up and I’m like, HOW CAN YOU THINK A MONITOR IS A GOOD MEDIUM FOR THIS BULLSHIT?! To even think about diagnosing DIchomatic, you need to go to optometrist. For any eye related test, you should see a licensed professional. Not your computer monitor with a gradient scale my 5 year old nieces could put together.

        It’s like people who self diagnose from WebMD.

      2. Purple is the hue of grapeskins, between pink and red. Violet is between blue and lilac. Lavender is pretty much violet and indigo pretty much blue. Blee/blea is the hue of fresh lead or the sky, between glass/emerald/teal and blue. Sometimes I distinguish blea and turquoise, which I call shore, where blea is between shore and blue.

  5. I would think that it would be easy to figure out now days. Does the television or computer screen look different or bland compared to real life?

    For me, the TV and computer screen look perfectly accurate as compared to what I see on a sunny day. I would assume that I can only see the red/green/blue – as that’s all that the TV projects and it looks real to me.

    Does this mean that I’m seeing these things accurately? I’ll never know that.

    My son was color blind and it took an eye dr to figure that out. He favored pink shirts and everyone thought that he was courageous and making a bold statement. Turned out that he had no idea that he was wearing pink. He got a lot of compliments, so he went with it.

    1. Funny you should say that… TV screens and especially Movies recorded on old film look really wrong. The colours are different (especially flesh tones). Colour looks more “flat” too… if that makes sense. I’ve always accepted that this is just a limitation of film / digital recordings but maybe I do see colour slightly differently to other people. In any case I have arguments with my family over blue and green all the time. I see things as more blue than they are according to my family (lots of things that I see as blue they insist are actually green). Rather than tetrachromat I think this means that I probably just have extra blue cones or that my brain weights colours more towards blue (which is also my favourite colour). I can’t look directly at blue LEDs or blue fluorescent lights (it feels like it’s burning into my brain with the brightness) but I have no trouble with red, green, yellow or white LEDs. Sunlight burns my eyes and I have to wear sunglasses most days (even on overcast days) or it feels like my eyes are being stabbed.

      1. You have photophobia, lol. It means you’re more sensitive to blue wavelengths. I have photophobia and I have a BFA in illustration- color is my livelihood. If I went outside into the sunshine I’d get headaches and constantly squint. Most indoor lights can aggravate my eyes as well- I buy Edison bulbs because reds are very soothing for me. The light from monitors (they use blue light) can cause me eye strain and lead to headaches later on. I wear a special set of glasses with a coating that helps dull down blue wavelengths to help my eyes not strain. It’s helpings me a ton. Though I dislike the fact it alters colors for me, so I find myself taking them off a lot.

        – – –

        Loved this article. I remember an article on the latest woman proved to have the 4th cone and she literally said: you have to train yourself to see that way. I’m just happy enough that I see pinks, purples, teals, and greens in the grey clouds. I’m sure my vision isn’t anything special, but I know I see better than many around me when it comes to distinguishing and separating colors within gray tones. I especially love distinguishing all the color variations in shadows- color training is great for anyone. That’s cool enough for me. x)

  6. Presumably one way to infer if you are a tetrachromat would be if there are colors you see in real life that never appear correct on a computer screen.

    1. I don’t think that’s a valid test. I’m pretty sure I’m not a Tetrachromat, but there are plenty of colours I can see in real life that I’ve never seen replicated on a TV or computer screen – the colour on those absolutely always looks off to me (which I’m sure it is given the technology limitations). But I’m just a normal person without colour blindness but with a strong interest in colour (and a good colour memory – I can often match fabric swatches from memory which is useful when shopping – doesn’t make me a tetrachromat though).

  7. I actually, honestly am a Tetrachromat, I do see more colors than normal. I respect you trying to do all this research but this article is not really true. It seems ignorant and rude excluding the Tetrachromats saying they aren’t what they are… Its in the title so don’t tell me that’s not what this article is about.

    1. With all due respect, no you’re not. Functional tetrachromacy is exceptionally rare. All the scientific evidence that’s ever been done on the subject supports that. And in thirty years of research, one single person has been found to have functional tetrachromacy. Chances are, you’re not that person. Maybe you also have it. But unless you’ve been tested in an appropriate laboratory setting, I feel 100% comfortable rejecting your claim to “see more colors than normal.”

      And finally, you think it’s rude of me to exclude tetrachromats based on an enormous amount of research, freely available online, and the fact that it is FUNDAMENTALLY IMPOSSIBLE to diagnose tetrachromacy on a computer screen, but you feel completely confident dismissing my work by fiat, telling me that what I’ve written is “really not true” based on what you think you know about your own eyesight. Maybe you should use your special eyes to take a good hard look at yourself and how you make arguments.

      I’ll make you a deal. If you can find one single thing in my article that’s objectively untrue, logically fallacious, or at all incorrect, point it out. I’ll issue a correction. If you have proof—real, scientific proof—that you’re a functional tetrachromat, contact Gabriele Jordan at the University of Newcastle immediately. I’m sure she’s dying to hear from you, especially since she’s the only person who’s ever devised a test for what you claim to have. If you prove me wrong, I’ll edit this post with a full redaction of whatever I screwed up on, like I already have with the parts about UV light.

      But until that happens, I’m going to assume that you, like the delusional woman who published this graphic in the first place, are grossly misunderstanding what tetrachromacy actually is, and whether you in fact have it. I look forward to hearing from you.

      1. Your article is excellent. Any of your colour deficit hasn’t stopped you from have an brilliant mind. My son is deuteranomalous and I know what a conversation looks like for him with those who do,and do not get what that’s like. Despite that some of us will have to forego feeling special, if we want to be critical of what is set up to be the truth. The optometrist that diagnosed my son used to do work for the military. During the Vietnam war people who were colour “blind” were recruited to review the aerial maps of jungle areas to detect “disturbances” in the green terrain that proved to be evidence of enemy activity. This was very successful until the opposition went underground…I can’t comment any further on the science, because it’s just not my field, but it’s encouraging to see this kind of dialogue here…especially for a father who is interested in science that makes a worthy difference I his son’s life. But alas there will be times, when we may all fall victim to the deceptive words of those fucking nueromarketers in the glossy pages of FB read in the waiting room of their local doctor’s office, waiting for a flu shot.. 😉

      2. Please look around to see if you can find anything about Concetta Antico being a tetrachromat

  8. I really like this article, because is scientifically grounded yet very readable and simple to understand. I have come across the term of tetrachromacy yesterday and it really amazes me … I believe in the science here, that it is very rare, at least in the population which has been tested for. For me, it is just the prove that ‘the magic’ really exists … in the sense of tetrachromacy, what is magical is the perception of the reality that our body is allowing us … is so much wider than normal, that normal cannot believe in it because for it, it doesnt exist! I can really see how these women with the functional four cone cell were seen as crazy and delusional through the history … however rare they were. And it comes to my mind the quote ‘and those who were seen dancing were thought to be insane by those who could not hear the music’ …. And I am just wondering how many different mutations there are in different bodies, and how astonishing fact it is, that our body, our senses, are truly our window to reality … So please, always believe in magic, because what is magic for someone, it just might be the reality for somebody else! 🙂 🙂 (and off course, there is also those who feed their egos by being magical all the time, but I am not referring to social disfunctionality here but more to genetic abilities ans social inclusion of differences…) ..

  9. Great article, I’m still intrigued by the subject, so will continue my search down the rabbit hole..I have recently seen an exquisite 360 degree google image of an ancient Temple of Hathor in Egypt. Eons of soot were cleaned off the ceiling to reveal blue the sky. I know you had mentioned it was called “golden” in ancient and biblical times. Interestingly, when I first saw this image there was something magical in that color…it was golden. You can go to google map/temple of Hathor at Dendera Egypt and then just get a live view, close as possible with the little man for the street view Enjoy! maybe we are all capable of tetracromancy
    …Here check it out,32.6703752,3a,75y,4.57h,167.06t/data=!3m8!1e1!3m6!1s-fJwyoDBFlC4%2FVm3jFFUtwUI%2FAAAAAAAAQEE%2FVNgd9lKnKvQAUA_IXJQNuzTrDJMnfgFtgCJkC!2e4!3e11!!7i8704!8i4352!4m13!1m7!3m6!1s0x0:0x55c5acd6d797167f!2sTemple+of+The+Goddess+Hathor+(Dendera)!3b1!8m2!3d26.1419501!4d32.670242!3m4!1s0x0:0x55c5acd6d797167f!8m2!3d26.1419501!4d32.670242

  10. So how do you explain that I see 39 colors as well as my father does, but both my sister and mother see less colors even less than 20? Does it mean they are color blind? I do undesrtand all your arguments and agree with them but I have the doubt about on why some people see less or more colors than the others.

  11. I took all types of test that said I was tetrachromat and despite defeating each one I was always thinking the words “horse shyt”. Mainly because like you said, my monitor can only have 3 shades of colors at various degrees creating the illusion of color. And the fact that color does not exist, color is created in the brain and used as our brain’s way of labeling each wavelength of light, for example, Pink does not exist in the real world at all, there is no color wheel. Our brains made up pink to connect red and purple. Pretty much it was our brains way of completing our color definition range. Light is light until the brain makes it something else, our brain knows when different wavelengths of light are entering the eyes when the cons in the eyes fire up and tell the brain…. thing is color is just labeling the many different various patterns between the cones. So yes even if you had more cones it would not change much sense the brain still uses the same colors to code each wavelength.

  12. Your title is misleading, you admitted there are tetrachromats. Also, one Jay Neitz, a color vision researcher at the Medical College of Wisconsin, estimates that half of the female population has a fourth cone in their eyes, and even 8% of men (three cone genes on the X chromosome, on top of the one on the seventh chromosone). There are more ways in which this is possible, than sone pll think.

  13. Long before computers were in homes and most businesses back in the early 80s, I worked in a photo processing lab. We had to do a color test using either chips or paper (I don’t remember), but I scored a “0”! I was told then that I was one of the few people in the country who scored that low, which is the best score you can get. So, I’m not sure where you got your data because I also took the computer test tonight and scored “0” again! I am a true tetrachromat!

    1. If you took the test on a computer, then it can’t prove you’re a tetrachromat for reasons that I explained exhaustively in the post. And I don’t know what test you took in the 80s, but it was probably testing standard color vision, since tetrachromacy is so rare that it would be pointless to even look for it.

      1. The test was just like the computer test… the color chips had to be arranged by shades and tints just like the computer test.

  14. Only two women empirically proven to be tetrachromats. How do they view the night sky, a rainbow, a forest (temperate or tropical)? I’ve used the color blindness filters for my camera, and the trichromatic algorithm is so much brighter than the dichros’. Three to four might only be a bit more colorful, based on Pascal numbers, and fractals, and, how, it occurs, rarely, but isn’t always detected. It’s mutations like these that can sometimes have an advantageous effect for a race of animals, but only when the advantage is necessary to survival, does it become desirable, and thus, shape evolution. We homosapiens can keep ourselves alive out in the elements, day to day life, just fine with three or less color receptors, it’s the depths and shapes that we need to move around. Colors are a luxury!

  15. This is even more funny if you consider that Diana Derval’s original image actually has over 10,000 distinct colors. That’s what happens when you don’t know what you’re doing and don’t understand what image compression does to images. Next time try GIF format or lossless PNG Diana!

    1. I could/can see hundreds and hundreds of distinct vertical lines of unique colours in that original image, due to the compression and pixel bleeding. Almost facepalmed right through my face when I discovered that that wasn’t intentional and it’s just artifacting and pixel bleeding, because it renders the entire thing even more useless than it already is. And frustrating, for people who can see the banding and told they’re lying because “it only has 39 colours!!1”

  16. Interesting article! It does seem that some people are more sensitive than others when it comes to seeing colours though. Is it possible that this might be to do with how many rods and cones you have? I wonder because I use colour in my work, but I have terrible vision at dusk to the point that I don’t feel safe driving.

  17. aphakia simply means a person lacks a lens in the eye. it has nothing to do with UV. the UV perception is a possible side effect, but aphakia is not defined by that side effect. Typically aphakia occurs due to surgical removal of the lens due to cataracts. If new lenses are inserted, the person is then pseudophakic, not aphakic. Very rarely humans can be born aphakic (without a lens).

  18. I mean, I’m sure they’re right and all, and I won’t defend the whole Tetrachromat thing, but the author of this article sounds butthurt as fuck.

  19. One minimal thing: Many mirrorless camera sensors (i.e. most digital cameras) actually do capture some infrared light. (This can be easily tested too, such as by pointing a phone at a remote.) Of course however the picture processing part interprets this as simply excess light accross channels, and that’s how the image gets written like.

  20. Interesting. Never heard about this. You say people from northern Europe are more likely to have it; Do you have a source for this claim? (Only because i want ro read more about it). I am a Norwegian woman and my father is red-green colour blind. If I would want to do a scientific appeoved test, is it possible? If so where should I go and who should I see?

    1. Honestly, I can’t find that source, and I’m embarrassed not to have linked it in the first place, so you’re welcome to be skeptical about that part. It was associated with the relative lack of melanin (blond hair, white skin, blue eyes) but I can’t remember much more than that. As far as doing a real tetrachromacy test, I have no idea where you’d go for something like that. If it’s administered via computer screen, though, it’s not legit. It would have to be carefully calibrated ink or paint swatches.

  21. I wonder if the rareness of functioning tetrachromacy, given how common the trait should be, genetically, might be due to habituation laziness. test and train 2-year old girls with the genes. See if it can be trained. — David Brin, author of The Postman.

    1. Normal Vision 92% (Red Green Blue and Yellow) 3 Cones and lot of 4 Cones.
      ___if u have 4 cones. there is no Diferent same Vision like 3 cones____ its not Ultraviolette or Infra Red light RODs.

      Deuteranomlay 2,7%

      Protanomaly 0,66%

      Protanopia 0.59%

      Deuteranopia 0.56%

      Tritanopia 0.016%

      Tritanomaly 0,01% ( mix of 2 Colorblinds) its not Tetrachromcy

      Achromatopsia 0.0001% (black and White)

  22. Vision is an interesting thing. So is perception.

    I have a lot of northern european heritage, my 23andme results report. While I can see colors others don’t seem to and can see way better at night, often opting not to use a flashlight at night even out in the country, two out my four children are colorblind — one son and one daughter. My other daughter is very sensitive to the differences between colors and may think colors clash, two different shades of red for example, when others seem oblivious. One daughter can’t tell all the different blues apart very well at all and the other one see a wide array of them. I’m not saying I and my one daughter are tetrachromats, but I do think scientists probably aren’t done exploring human vision. Maybe they’re not even close to being done. If they were, maybe it would revolutionize indoor lighting. Personally, I think my eyesight is most likely just an adaptation to ancestral lands that had long, dark winters. That seems to make sense anyway.

    Interestingly enough, both my daughters like the arts but the colorblind one works almost exclusively in graphite pencil while the other is now exploring painting too. Painting with a limited color palette increasingly fascinates me, it’s the whole making so many colors from so few deal.

    That brings me to this; I think the real gift is enjoying what you’ve got in ways that make sense to you. Why do some go that gaga over tetrachomacy being a special gift when we can all advance our skills and senses so much just by exercising them, with some instruction hopefully. That’s potentially far more fascinating and impactful, as interesting as tetrachromacy is.

    Sadly, shop and art classes have been cut from school budgets for decades in many places. Formal art education has been hobbled in other ways for about a century. The language arts have suffered too, in the US. It’s no use for a society to refuse to push skills to their outer limits, all while leaning toward a disproportionate focus on high IQs, tetrachromats, and other special inborn traits.

    So yeah, the science of vision rocks but both vision and perception are affected by how we exercise and train them. If you blindfolded a tetrachromat from birth, their bain wouldn’t learn how to see, vision is a brain-eye thing, and they would essentially be blind even if you took the blindfold off when they were 30. If you took that same child and instead of blindfolding them, you immersed them in the arts, they could more fully enjoy being a tetrachromat. The same would true for people with different sorts of vision or other traits — let each develop and bloom with what they have because that powerfully and functionally changes what we have and who we are.

  23. My wife is terachromat, and aphakia thanks to a slight genetic anomaly. [which probably means the genes are close to one another] I have normal colour vision, but a mutated form of *rod* cells that are somewhat more sensitive to far-red light bordering on infra-red… and our daughter inherited all three mutations. Her visual spectrum ranges from infra-red, through to UV, with far more ‘stops’ along the way.

    As you can imagine… agreement on exactly *what* colour something is, is next to impossible!! We’ve pretty much all agreed to stick to wearing black or muted colours, for obvious reasons.

  24. all the People made the Test. had the Hope to be Special and better as all the other…

    u can be happy you are not Blind. be happy you can see everthing.

    this Tetrachromate are fake. …

    this Womans are Dauters of colorblind parents and see only 50% of Trichromants. its a Handicaped. cant work in every job. are Disabeld.

    but think are better as other Dichromate colorblind. becouse can see litle bit normal Vision.

    close 1 Eye so is Dichromate. and 100% colorblind.

    Moving head. the colors change. and this isnt Tetrachromate.

  25. Europeans are mostly Colorblind. becouse long Winter and Neandertaler Gen.

    all the old Testet People was Europeans. not testet in Afrika. or Asia. just europeans.

    in the old colonies there are lot of Colorblinds. 8% of Europe are colorblinds.

    and 0,0001% Asians or Afrikans are colorblind. becouse have lot of Vitamin A. in the Gen.

    Blue Eyse. White skin. are 90% Albinos. no Color Pigments

    1. Where did you get your [malnumerate Napoleonic notation] figures?

      Hair has three pigments, one (black) more widebandly darker than the others. it’s completely useleas as a retinal color pigment. Can the white skin tan or not? Not that this speculation matters any; the two lower cone pigments should correspond to violet and dusk, not seen in skin or hair.

  26. Nothing is more annoying than arguing that there is a thousand (or more) different colors of each basic color with someone who can not see what I see.

    I’ve never gotten less than 98% on any shade test done (not on the computer but for a CAR quality control company), and no matter how mutated it is or isn’t, or how many cones it is or isn’t, or how many different animals see as I do… the shit is annoying to have someone literally blind to what I’m seeing and arguing with me about what I see.

    I also don’t believe anything is bullshit because people haven’t been found with it. For the first thirty years I never thought much about it, and assumed people saw similar to how I do.

    Even the color example at the top is in the wrong damn order and it’s bothering me.

    I want another planet.

  27. The funny thing is, apart from people missing one type of cone, there is no such thing as color-blindness. As explained, we only have three sensors for the whole spectrum of visible light. Because of this simplification, there are many different spectra that will look the same even to non color-blind people, although they are different (check metamerism). People we call color-blind only have a different “blind spot” than so called normal people. This means that they also have the “ability” to tell the difference between colors that look the same to normal people. But we call them color-blind simply because we focus on how their difference is a problem in daily life.
    So people who claim to be tetrachromats might just be what we usually call color-blind.

  28. I have been in a full blown argument with my friends over the color of my shirt. My friends keep telling me it is strictly green..Where as I am DEAD set on the fact that my shirt belongs in the Teal color house. It is not a proper green, it has blue in it- and I can see it, and nobody else can seem to pick it out, it’s driving me CRAZY. It was making me feel fricken INSANE until I realized that being assigned female at birth, there was a chance I saw more color than some of my friends do. I still stare at this particular shirt with a touch of disdain, even though I identify as male now- but knowing that there is a chance I could be a tetrachromat, makes me happy, and secures the fact that I am certainly right that my shirt really does have a ” blue – green ” hue to it.

  29. Good article… but you made one mistake: “ANY COLOR IN THE WORLD THAT IS NOT A SPECIFIC WAVELENGTH OF RED, GREEN, OR BLUE”

    Pure-frequencies are also shoe-horned into a mixture of three response levels from the three color sensors. There is enough overlap in the bell-shaped response curve of the green and red sensors that a pure red laser, for example, is going to tickle the green receptor a little, and even the blue receptor may respond ever-so-slightly.

    More correct to say any spectrum (mixture of varying levels of all frequencies) is shoe-horned in the the response levels of three color sensors (in the normal human eye).

  30. Please explain why EVERYONE neglects rod-cells.
    Rod-cells should participate in “Photopic vision” along with cone-cells.
    If you look at the rod sensitivity spectrum you will see them respond to Cyan color channel.

    I argue that every human has capacity for tetrachromacy because of the rod-cells.

  31. Thank you for an interesting article which could possibly explain why I have had so many arguments about colour over the years. I am 67, female and an artist and there is colour blindness in my family.

    For me the world is and always has been a kaleidoscope of colour as I appear to be able to discern shades that other people equally appear quite unable to detect which is where the arguments came in when I was younger, though these days I keep my mouth shut and just accept that people see things differently.

    I love being able to pick out the subtle colour variations in nature especially things like feathers, puddles, and even snow and ice and in the right conditions I can sometimes discern a touch of reflective light like a multicoloured sparkle in the air around me which I have to admit had me worried at one point because I have never met anyone else who could see that so I thought I was going batty.

    The downsides are I am never satisfied when I try to draw something from nature and it can be a nightmare trying to colour match anything as the differences between two shades of colour can be glaringly obvious; well to me at least. Plus, though it may not be connected, all of the migraines I have had in the last couple of years have been aural so affect my sight which is not at all funny when they happen.

    I can’t say whether any of this is down to an extra cone or not but it’s nice to know it might have a simple explanation. But for the many of you who seem convinced you are because of that very poor image bandied around the internet please note I gave up counting bands on that image when I passed 50 and still had a long way to go! Please remember computers are still in their infancy, it’s not so long ago that they could only display white or green on black, then for many years colour meant a meagre 256 shades and even today’s monitors are not a patch on the human eye so as the writer of this piece suggests you will need to complete a proper none computer generated test if you really want to find out.

  32. I see people saying they’re tetrachromatic in the comments.. LOL. Some people are just desperate to say or think that they’re unique for something. A lot of them actually convince themselves that they are because of some shit that happened in their life.

  33. This is one exceptionally well written and entertaining article! Not at all an area of intrest for me and yet I found myself deeply interested. Very educational, witty and easy to digest, not to mention funny. The way you make your arguments…have you by any chance studied philosophy? Thanks for a great read.

  34. I wish I could take a genuine test. My son has red/green color deficiency. He is an artist, as are most in my family. I can paint, (though not that well, which is why I am a lawyer😛. But still, it is a lifelong hobby. I love complex color combinations. For instance, when I paint a sky I may mix 40 or fifty different batches of color. I see them clearly, but even the artists in my family don’t see many of them, even when I point them out. I’ve always thought this a bit weird, but it appears this sort of test is not readily available so I guess Ill never know!

  35. if you were a tetrachromat you would see a whole new primary colour apart from the rgb (red, blue, green) that general people see. it’s possible that one trichromat can differentiate colours better than another but being a trichromat he can see only 3 primary colours. tetrachromacy tests can’t be done on normal computer/ phone screens as they have 3 just 3 primary colors rgb. if u want to check tetrachromacy you’d need a device which is built of 4 primary colours rgb and another color. Im assuming tetrachromats can see a uv light or ir light but lord knows about that

  36. I came across this article when I searched for information, are there a humans who see ultraviolet light, to understand if I can.
    Yes, the Web is full of bullshits, only for to attract the attention! I see that here the question is presented more realistic and understandable.
    So, what is my case: I haven’t noticed to see different colours, but I can see when the UV index is high and when it is low. But I see it not with colour, and as a transparent light, very similar to the visible white light, but more bright. I see how UV index is highest in the summer and is lowest in the winter for example. What do you think, is this has something to do with the tetrachromacy or with the ability to see UV light?
    P.S. I’m a woman, don’t have aphakia or lens removed or whatever, and don’t have relatives with color blindness.
    Sorry for the bad English, it’s not my native language.

  37. I feel sorry for all of the people who are saying they are a REAL tetrachromat. Doing an online test will certainly not show if you have this ability. I have been back and forth from optometrists saying that I am an unusual specimen of human species. I was born with a mutation of my eyes, letting me see UV rays, causing tetrachromacy and a mutation in a certain chromosome, causing an electric blue eye colour and wider colour spectrum. I pity people that are fakers and say they have this condition, because they are lying and do not know what they are talking about. This is a serious medical condition, not a game so do not claim to have this condition.

  38. This is rather interesting. I tend to agree with you that those tests are BS, if for no other reason than the fact that monitors need to be specifically calibrated in order to have any hope of testing anything color specific. At which point you run into the issues that you mentioned about monitors not being capable of displaying the necessary colors to make a test work at all.

    What makes a proper diagnosis even tougher is that our eyes don’t necessarily all have cones that are tuned quite the same way, so you can have somebody with the regular number of cones that are all functioning, but aren’t tuned quite the same way.

    One of the reasons I’ve become interested in this is that it appears that I’m seeing colors that can’t exist, but don’t have much trouble passing color-blindness testing. I see a secondary set of flame on candles and when the lights go out completely, I can still see the basic shape of things, even though I’m the only one that can. Which leads to the question of whether it’s the number of cones or how the cones are “tuned” that is the issue.

    As far as it being impossible for somebody with XY chromosomes to be a tetrachromat, that isn’t how genetics work. The reason why colorblindness is so much more common in men than women is that if it was omitted on the Y chromosome, then the genes act like you got two of whatever the X had. If it’s on the remaining portion of the Y that matches the X, then it’s no different whether it’s XX or XY, you need two copies for a recessive gene to express itself.

  39. Yes, I claim to see nuances in colors others don’t, but also I would love to think I was “special” …LOL. This why stories like this go viral.

  40. My mom walked in on me reading this article right when the cat was head-butting the horse. We both thought it was cute and watched it for half a minute, before she said, “What the fuck are you reading?”

    To which I responded, “Possibly the coolest blog ever!”

    Keep it up dude!

  41. This link explains why most of those are complete garbage. And my thanks to Unreasonably Dangerous Onion Rings for taking the time to debunk this so that I could spend my time writing novels.

  42. Fascinating stuff. Now I have a question, not that relevant, but…. I’m male and not remotely tetrachromat. I can distinguish all the Ishihara colour vision tests, no problem. But here’s the thing – When I see a traffic light in the distance, it always looks blue; only when I get up close to it does it look green. My wife has no such problem. When I was young my father and I swore that a new pair of socks was brown while my mother, sister and brother said it was green (I think it was that way round). I went for a job on the railroads and they put up coloured circles for me to identify; I stupidly did not realise what it was all about – railway signal colours, I was fine on red and yellow – but reported the green as blue (which to me it was); She then put up a proper blue (as I found out later) which I correctly identified, then back to the green which I reported as a sky-blue after she pushed me on my answer. I have lots of arguments with my wife over clothing colours particularly in the green-blue spread and also on the red-orange boundary although to a much lesser extent. So my question is, are there common variations in human colour cell genetics that lead to real variations in the rhodopsins employed, that can be inherited down the male line, and that result in a variation in perceived colour? I’m guessing something is off about my blue colour sensor, assuming this is not a cultural difference.

    If I get hold of a few prisms or graduated multilayer dielectric filters, plus a strong light source and a humungus amount of patience I can identify a set of metamers to determine the spectral responses of each cell type??? Or is that rubbish?

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