I was recently asked to expound on colorblindness. Unfortunately for you, colorblindness is one of my most favorite topics. I’ll try to keep it toned down a bit so I don’t get too hyper and long-winded.
Colorblindness comes in varying shapes and forms. Some people are completely colorblind, some have difficulty with only certain colors, and others are so mildly colorblind that they go through life completely unaware. Colorblindness affects about 1 in 9 males, and because it is passed along on the male gene, it is generally quite difficult, though not impossible, for a female to be colorblind. Colorblindness can also be caused by chemical interference, accidents, and brain injuries although this type of colorblindness typically only affects one eye and may not be permanent.
Some of the more common myths are that colorblind people simply cannot see a color or that a color is replaced with another. Not true. Colorblind people can generally see any color you can but may not readily identify it or may have trouble distinguishing between one color and another. This does not include total colorblindness. To help explain, let’s explore what colorblindness is a bit further.
Everyone’s eyes are made up of light-receiving cells known as cones and rods. The cones are primarily responsible for interpreting color, and they come in three styles: red-yellow, yellow-green, and blue if my memory serves me. Each cone is triggered by a range of color. When the cone perceives that color, it sends a signal to the brain. The combination of all the signals allows the brain to create the “picture” in full-color. A colorblind person, however, has a deficiency in their cones. Instead of the normal amount or abilities of all three cones, one or more types of cones are lower in number, damaged, or even entirely absent. If they are absent, the person is totally color-blind. If they are reduced, they are only partially colorblind.
Most colorblind people are red-green colorblind meaning that they have a deficiency in either their red-yellow or yellow-green cones. Because of the deficiency, the color is registered by the next closest color receptor. That makes the color “slide” a bit on the color scale and creates the replacement that most people think happens. In reality, the color is still accurate and even seen, but it is more difficult to distinguish some of the subtleties. In my case, I have deficiencies across all cones, but more generally in the red-yellow or yellow-green. I am a classic red-green colorblind person with some deficiencies elsewhere.
To help a little more, I once came up with this explanation to help people understand colorblindness. Look at your computer screen very closely. You’ll notice that it is really made up of red, green, and blue dots. When all dots are shining bright, you see white. When they are not, you see black. When you combine the red and blue, you see purple. You can combine these three colors into a seemingly infinite arrangements of colors. This is known as the RGB color theory (r = red, g = green, and b = blue). Our cones approximate the RGB color theory except we have a touch of yellow in our red and green. Going back to the computer, what would happen if half of your red dots suddenly quit working? You’d still see red, right? Of course you would. But what about when red was combined with blue to make purple? Well, you don’t have all the red anymore, so what do you see? Blue. That is, of course, a dramatic example, but imagine that, like most colorblind people, only a small portion of your dots weren’t working right. Instead of a complete replacement of color, what you would see is a slight color shift. Instead of a deep purple, you might see a slightly lighter purple. That is basically how colorblindness works.
For most colorblind people, it isn’t really that big of a deal. I dress myself just fine with only the rare mishap. I can drive just fine even though what I see on a stop light is closer to white, orange, red. The biggest problems for us are when people put a color on a slightly darker or lighter color with a similar tone. Or worse, green on red. They are just difficult to see.
So there you have it. A shortened version of my usually lengthy expose on colorblindness.
Oh, and just to cut it short… MOST colorblind people find it highly offensive when they are asked the standard “what color is this?” question. For MOST colorblind people, it is somewhat akin to walking up to a person in a wheelchair and asking them to dance. I personally do not mind the question because I understand that most are just genuinely curious. But the next time you meet a colorblind person and have the urge to ask, start by first asking them to explain colorblindness. It changes the tone of the conversation from “Hey! Look at the freak-show” to “I’m interested; tell me more.”
And for your fun little bit of trivia, yellow is the favorite color of a large number of colorblind people (remember they are mostly males) because it is the only color covered by two cones and, therefore, is also generally the only color that almost every colorblind person can see.
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