Colorblindness
May 3rd, 2005 by Steve Pavlina
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I’ve been red-green colorblind since birth, and someone told me about a site with some neat photos that reveals how people like me perceive colors.
If you visit that link and scroll down a little, you’ll see two pictures of a fruit vendor. The first picture is normal. The second picture is how red-green colorblind people see the first picture. For me the colors in the two pictures are identical.
Scroll down a bit more, and there are pictures of some cells. Both pictures look the same to me.
Then further down there are some colored dot pictures. I remember failing a lot of tests like this as a child. I can’t see anything but random dots in the top two pictures, but I can clearly see the number 45 in the bottom two.
When I showed my wife these photos, she got a bit emotional, reacting as if it suddenly dawned on her that I’m afflicted with a terrible handicap. She said now she understands why I have so much trouble picking decent fruit. She also said she’ll never again ask me if her outfits match. 
I have no idea how people without colorblindness perceive colors, but at least these images allow people with normal color vision to get a glimpse of what the world looks like to colorblind people. People with normal color vision can see certain colors that I’ve never seen in my entire life, so I can’t even fathom what they must look like. Even in my dreams I still perceive the same colors I do when I’m awake as far as I can tell. How could you dream about a color you’ve never seen?
It would be strange if colorblindness were someday curable. Imagine perceiving new colors you’ve never before seen. Now that would take some adjustment. Even people would look very different.
Functionally I’ve gotten around colorblindness by relying on other data. I can’t really tell if a banana is yellow or light green (both colors look the same to me), so I look to see if it has spots and check to see how soft it is — I ate 4 bananas today, and all of them had spots — if they don’t have spots, I tend to avoid them, or I ask someone else if they’re ripe yet.
When I was first learning to drive, I sometimes had trouble telling the red light from the yellow light if the red light was very bright. But I quickly learned that the red light is always at the top (at least in the USA). One time though I went through a flashing red light thinking it was a flashing yellow light (so I merely slowed down instead of stopped). There was only one bulb on that signal, so I couldn’t tell what color it was by its position.
When doing artwork for computer games or web sites, I rely heavily on the RGB values. That’s the only way I can tell certain colors apart. I never pick colors visually, such as by using color palettes or color wheels. I’ve memorized the RGB values for the colors I use most, so I just type in the RGB for any color I want. Yellow is RGB(255,255,0), and bright green is RGB(0,255,0) — that’s the only way I can tell those two colors apart because on the screen they look identical to me. Even if I put them side by side, I can’t perceive any border between them. This crutch of using RGB values helps, but it still doesn’t prevent me from making odd color choices that look right to me but perhaps not to everyone else. That works both ways though — there are web sites that look odd to me color-wise that probably look OK to non-colorblind people.
Of all the birth defects I could have been born with, this one doesn’t seem too bad. In fact I find it somewhat amusing — like a cosmic joke. It’s ironic that someone who can’t pick produce properly ends up becoming a vegan. At least I married a color-seeing wife. The way she’s able to pick good produce is almost magical.
May 4th, 2005 at 12:33 am
I heard of an instance where this disability turned out to be an advantage. A friend of mine who flew fighter bombers in Korea had a colleague who had an unerring ability to pick out camouflage nets over potential targets in the jungle. It turned out that he was color blind and had cheated his way through the pilot’s examination by memorizing the numbers in the colored-dot tests, and he saw the camouflage completely differently from what it was intended to look like.
May 4th, 2005 at 1:21 am
This is so very interesting. I’ve never understood colour blindness before and reading your post and checking out the pictures at Vischeck has finally made it click for me. If I thought about it at all before, I always thought it was just some minor lack of visual adjustment that meant colour blind people couldn’t be pilots. Now I get it.
I love stuff like this that helps people understand each other better.
May 4th, 2005 at 1:31 am
Time Management and Perceptions
Over at the YoungEntrepreneur.com forums there is a discussion about time management. Another member posted a link to an article by Steve Pavlina titled Do It Now. It’s a lengthy article so set aside a good 20 minutes to digest…
May 4th, 2005 at 8:04 am
Hi Steve, I always wondered about the color selection on Dexterity.com… it seemed less professional than your other efforts. Now I understand
May 4th, 2005 at 12:31 pm
My sister used her husband’s color blindness to her advantage — she got the pink house she always wanted…and never told him.
May 4th, 2005 at 10:42 pm
Nice! I have a younger brother who is deaf so I understand that one. I have to say I would rather be color blind than deaf, but that is from a musical standpoint.
May 4th, 2005 at 11:01 pm
Hmm.. steve is also color blind. Is it just me, or are all successful people color blind? (I know another guy that I idealize, and he’s color blind too)
May 5th, 2005 at 3:49 am
anonymous: AFAIK, Dexterity.com was all yellow-blue, so there’s no connection.
May 5th, 2005 at 2:44 pm
My computer monitor has individual adjustments for the percentage of the R(ed), G(reen) and B(lue) values of the monitor image. Normally they are all at 100%, so I see everything on the monitor just like in reality (I have “normal” color vision).
But when I set the value for red to zero, I found out that I can easily simulate red-green colorblindness. This “simulation” isn’t perfect, but I don’t need to have extra hard- or software.
Setting red to zero, I also fail in tests like these “Colour Blindness Tests”:
http://www.kcl.ac.uk/teares/gktvc/vc/lt/colourblindness/cblind.htm
And the pictures at the site you mentioned also appear to be (almost) the same then.
May 7th, 2005 at 1:38 pm
The protagonist of Robert Sawyer’s latest novel (”Mindscan”) is colorblind. When he has (a copy of) his mind uploaded to a new body, his colorblindness is cured. Some interesting passages on what its like to suddenly see “new” colors.
May 10th, 2005 at 1:11 am
Well, I think Dweep looks very good though. If you drew it all by yourself then congratulations. If you outsourced it than you had to trust the artist quite well!
This article link about colour-blindness was very valuable info for me, thanks!
June 1st, 2005 at 3:55 am
I should note here that this kind of colorblindness is not an either/or thing, but rather a continuum. For instance, I can’t see the 45 (although I can tell that something fishy going on there) but I can usually tell a green banana from a yellow one and DEFINITELY a yellow traffic light from a red light. I can tell RGB(255,255,0), from RGB(0,255,0) easily side by side, but I might occasionally label an isolated light green as yellow, or a light blue as purple.
(And yes… the color blindness tests freaked out MY wife too!)
June 1st, 2005 at 11:53 am
You’ve go to see this exploration by Wendy Carlos, a musician:
http://www.wendycarlos.com/colorvis/color3.html
Do you (if you can see red and green) consider yourself color blind because lots of bugs and birds see ultraviolet?
June 13th, 2005 at 1:44 pm
Have you guys heard of human tetrachromates, who have four color cones instead of three and who can see colors normal trichromates (having only three color cones) cannot see? All of these human tetrachomates (and there are very few) are female. Just as trichromates can discriminate between colors that look the same to color-blind dichromates, so tetrachromates can discriminate between colors that look the same to trichromates.
Question? Are trichromates color-blind relative to tetracromates, just as dichromates are relative to trichromates? Or are they just differently color-sensitive? That was a PC joke!
There are also other animals (birds, I think, and maybe some insects) who are tetrachromate and even some who are pentachromate (I think that’s the word for it), with five color cones. Are we color-blind relative to them? Yes, I think we are. Our color senses don’t give us as much information in response to different wave lengths of light as theirs do. And, of course, many four-legged mammals are dichromates. So they are color-blind relative to animals with more than two color cones.
So, if you happen to meet a tetrachromate who tells you that you look flushed, pay attention. She may be telling you something!
July 22nd, 2005 at 4:47 am
Hi would just like to say that I being colour blind did not find a problem distingishing RGB(255,255,0), from RGB(0,255,0). I also found that I could see the 5 fruits in the first pic. Apperently I am weak in red however I have only ever found this on the tests. Traffic lights are no problem for me and I have never got confused between a green and red flashing lights. I have found that it’s justthe accasional shades that i get wrong normally blue/purple red/brown red/green as the red eliment must be slightly weaker. This however is a majorly overplayed issue I would like it to not be an issue attoll unless you suffered from not being able to distingish basic colours such as the prime colours. The fact that this is able to be used as a discrimination excuse for employers is unacceptable. There is a cure in development useing gene theory which I am awaiting as I want to be a pilot.
I would also like to see more education in health professionals to be able to let the less effected colour blind people just live like normal people. I suffer from nothink else and did not even relise I was colourblind untill I did the stupid dots test. If not I wouldn’t even know now. There could be a much higher number of suffers out there who didn’t even now. Therefore why is it played up to be a probblem. I have not yet come across any evidience to show that being colour blind has caused crash, explosions or desasters. Its just played up to discriminate aggainst normal people!