About 8% of the male population has some form of colorblindness. In this article we’ll take a look at the basics of how colorblindness works.

A quick introduction to colorblindness

A quick introduction to colorblindness

About 8% of the male population has some form of colorblindness. In this article we’ll take a look at the basics of how colorblindness works.

To see anything at all we need some tiny little helpers inside our eyeballs, the so called photoreceptors. There are two different types of them: rods and cones. Both of them are sitting on the retina at the back of your eye and pass information on to our brain. The rods are sensitive to light while the cones pick up color.

Each of the cones is carrying one out one of three different photopigments – red, green and blue – and reacts differently on colored light sources. For each of this three types there exists a specific color absorption curve with peaks at different points in the color spectrum.

Mixing together the information of those three different types of cones makes up our color vision.

Now, when one type of cones malfunctiones the color this cone would normally absorb is altered. This changes the color perception, resulting in a (somewhat) different way of perceiving color. This is what we call colorblindness.

Types of colorblindness

The tree types of cones translate into tree main types of colorblindness: Deuteran (green), Protan (red) and Tritan (blue).

In each of these cases, the affected cones can either be mutated or defective. A mutated cone causes a slight shift and a defective cone causes bigger shift in the color perception. This results in a total of six types possible types of colorblindness.

The Deuteran (green) and Protan (red) inefficiencies are the most common ones:

  • Deuteranomaly: malfunctioning green cone (common)
  • Deuteranopia: missing green cone (rare)
  • Protanomaly: malfunctioning red cone (rare)
  • Protanopia: missing red cone (rare)

Blue-type colorblindness is also possible, but very rare:

  • Tritanopia: missing blue cone (very rare)
  • Tritanomaly: malfunctioning blue cone (very rare)

It’s a male problem

About 8% to 10% of the male population is colorblind. Colorblindness is most present in males due to the way genetics work (see footnotes). Only an estimated 0.5% of the female population is colorblind. Tritan-type colorblindness is not gender specific, women and men are equally affected.

Type Prevalence
Deuteranomaly (green) 4.63%
Deuteranopia (green) 1.27%
Protanomaly (red) 1.08%
Protanopia (red) 1.01%
Tritanomaly (blue) 0.02%
Tritanopia (blue) 0.03%

It’s not all black and white

There are many people who think the colorblind can’t see any color. But the term is misleading, more than 99% of all colorblind people can see color.

As you can see, people with the two most common types of colorblindness – Deuteran (green) and Protan (red) – don’t really suffer a radical change in the way they see color.
However, they do have limited ability to distinguish between reds and greens (and any other color that has their missing color in it), especially in shades of a certain color. Something might look green, but in certain situations it could also look red or blue.

The red and green cones lie quite close to each other in what colors they perceive (see the graphs above). They intersect at various points; when the green cones don’t work, the red ones still pick up some green – and the other way around.
The greens might not be as green as a non-colorblind person would perceive it, but it’s still within the category we would call green.

The Tritant (blue) colorblind have the blue end of the spectrum missing or altered. There is very little intersection between the other cones, this explains the big change in color perception.

The following table lists some of the most problematic colors for each main type of colorblindness:

Type Problematic colors
Deuteran (green) Green/red, green/blue, green/gray, green/brown, blue/purple, orange/red, yellow/orange.
Protan (red) purple/dark blue, orange/green, brown/dark green, red/brown, green/yellow, gray/purple
Tritan (blue) blue/yellow, violet/yellow-green, red/red-purple, dark blue/black, yellow/white

In conclusion

All of this might sound very medical and confusing, but the basics are very simple;

The colorblind have a narrowed color perception. Green is still green and red stays red most of the time, but not as vibrant or bright as a non colorblind would see it. Colors lie closer to each other, especially shades of colors.

In the next articles I’ll explain how these basics of colorblindness translate into practical difficulties, common frustrations and (usually) easy solutions.


The two common types of colorblindness (red-green and green-red) are the types of colorblindness that will be most discussed on this site. There are various other types of colorblindness with different perceptions, mutations and causes; they are however quite rare.

So as not to confuse the message with different clauses or oddities I won’t focus too much on these other rare types in general examples or articles. However, in the end any given solution or analysis will also work for these types of colorblindness.

Much of the information above is based on and used with permission from the most excellent colblindor.com by Daniel Fluck. More information on the working of colorblindness can be found in the Colorblind Essentials series.

For more information about the genetics side of colorblindness, take a look at this article on colblindor.com



  1. Nikhil bhatt

    No it dont matter it is only a matter of chance this is genetical disorder so it can also skip your offspring and may effect to your grandson/granddaughter

  2. Travis

    Great job on this article, informative in a very easy way. I’ve been color blind for years, and haven’t until recently gotten into the science behind it all. If anyone’s interested in checking out cool color blind tests and more info, there’s more at http://colorblindtest.info/

  3. joyt

    my son is 16 and we learned of his color deficiency when he was 10. I informed the school and teachers, but we didn’t talk much about it much until recently while taking about preparing for going to college and him getting ideas of his career path. he wants to be an engineer (architect). he is primarily red deficient and has given us examples of situations at school where he was confused with colors. iI want to talk more about his thoughts on dealing with confusion and taking a look at recognizing when he’s confused and how to seek help from others (and how that’s acceptable) but when we try to talk about his color deficiency he seems to get frustrated and annoyed. it’s evident that he wants to ignore it or as he says that he’ll ” work around it” and that ” color is stupid”. how can I get him to open up?

  4. AnjelinaRenita

    I was the only one who get colour blind on my family.My friend teasted me at school because they always say”hi colour blind bitch”since they know i was colour blind:,(
    i was colour blind to red/orange,yellow/white and purple-violet/blue-ish.

    • sunny

      hey, dont get upset, i m also color blind and mr Mark zukarberg, the FB CEO is also colorblind, still he is in tops.. so be positive

  5. Jared Shrewsbury

    I have a very hard time at school because I am colorblind, other people tease me and I’m wondering what I can do to help them understand what it is like to be me, any ideas?

  6. connie

    I have 2 sisters and we’re all 3 color blind.We have 1 brother who has just a little problem ..Is this unusually..

    • Nikhil bhatt

      Dont be worry it can be heppen in most rare cases

  7. prerna verma

    my brother is colour blind…is dre any solution fr dis!!
    plz advice me any way..
    as dre are chances dt he mmight face prblm in getting his job..

    • Vivek verma

      No ,there is no chance to solve this problem because i am also facing these problem .

  8. prerna verma

    my brother is colour blind…is dre any solution fr dis??
    as he might face prblm in gettng his job..
    plz suggest..

  9. Jacob Traylor

    Ive been diagnosed with protanopia and deuteranopia. My dad has both of these and my brothers don’t except one has the partial deuter. I forget what that one was. I was wondering how rare is it to have both of them? I can distinguish red and green at traffic lights just fine. I feel as though having both somehow counteracts each other. Does that make since at all?

    • Kevin

      I have a red weakness; my red cones are messed up. The simulated images do not look right at ALL. Few people have colorblindness as intense as those simulations.

  10. Anthony J Visconti

    If you are color blind what does simulated color blindness look like?

    • Adam

      The normal vision and the colorblind example are indistinguishable to a colorblind person. That is the whole point.

    • Jared Shrewsbury

      It looks normal

  11. franc

    I myself have a hard time seeing red and yellow colors and my eyes are real sensitive to sun light and artificial light . I sometimes wear sunglasses. 24/7 . Why? Anyone

    • Michael

      I am the similar. Reds show up but yellows are really muted. I wouldn’t notice but I am more color blind in one eye than the other. I have difficulty not squinting in full daylight. The brightness is so intense I need to wear sunglasses to keep from getting headaches or sneezing uncontrollably. I have pronounced tritanomaly (yellow/blue) in my right eye, but less pronounced, nearer normal, in my left and very light blue irises. My left eye is near 20/20 and my right is 20/200.

      If I am driving without sunglasses on and have to quickly shift my vision across the sun, I also slightly, involuntarily, jerk my head back when the bright passes direct accross my field of vision. It’s like the light itself is poking me directly in my eyes. And that’s why I flinch.

      Everyone who can see, has a similar reaction, if the light is bright enough, though. Ours is just far more sensitive. I’m not sure if it’s directly connected to color-blindedness, however.

  12. ThatHighSchoolKid

    Hello. I am doing a project in Health Class this year on Colorblindness! Do you have any articles or websites (besides this one) that you recommend for me to use in the paper?

  13. Melinda Beck

    Hi Tom– This is Melinda Beck, one of the health columnists for The Wall Street Journal. I’m working on a story about color blindedness and just found your site. Would you have time for a phone interview today or over the weekend? (that is, Nov. 2-4?) my deadline is actually today, but I can add to the story up until Monday. We are also hunting for high-res versions of photos like the hot-air balloons you have above, that show what the same picture looks like in various degress of color deficiency. Would you have a high-res version we could use or know how to get one? Thanks for your help-Melinda Beck, 212-288-0270//melinda.beck@wsj.com

  14. lena

    Well, I’m a woman with tritanomaly, so yes we do exist :)

  15. kajal

    I want to ask that if a mother is colorblind so who will be colorblind : her son or daughter?

    • Laura

      Most likely the son. The daughter can only be colorblind if the father is colorblind.
      And even so, it’s only a 50% chance that the son will be colorblind if the Mom donates the malfunctioning gene.

      Coming from someone who’s colorblind and has looked up this stuff a lot.

    • Kolia

      No, if the mom is colorblind, all of her sons will be too, since the X gene in men always come from the mother. If she is colorblind, then both of her X genes are mutated, meaning that whatever part of her 23rd chromosome she gives, she’ll give a mutated one. Since the men lack the other X gene (that could compensate and give them normal vision), it is sure they will be colorblind.

    • Amanda

      For someone who has “looked up this stuff” you have your information wrong. Color blindness is a mutation on the X chromosome. If a woman is colorblind then all of her sons will be too since she passes on the X chromosome to them. As far as a daughter, both X chromosomes would have to be compromised as well because if one isn’t then it can compensate for the other. Women are mostly carriers but men are more affected.

    • Jared Shrewsbury

      Only deuteron colorblindness is caused by the X chromosome, other types can be caused by other things, but not all color blindness is caused by the X chromosome, I have been diagnosed with deuteron color blindness and often research colorblindness.

  16. Michelle

    My grandmother was colorblind- so all her sons and grandsons are. Both of my sons are also colorblind. I’ve had such a hard time with testing at schools and technology used by schools. I have to have a mini-workshop for my boys’ teachers every year but don’t know how many understand. Love your blog!

    • María Ortiz

      Today, My 13 year old daughter took a standardized test at school. She had to request a black and white copy or version because it was red and white. Please share details about those mini workshops!!! I feel I might need those for my daughter’s teachers!!!

  17. Joaquin

    Why do you speak of the male population? Aren’t there any colorblind women?