Mind & Body

Do You See the Same Colors as Everyone Else?

Ever find yourself lying on the ground, staring up at a clear blue sky with a friend by your side? And while you were doing that, did you ever think to yourself, "I wonder if my friend sees the same blue that I see?" The more you think about it, the more it drives you wild — for all you know, if you could slip behind your friend's eyes, you'd see that the color they call "blue" is what you would normally call "yellow." Is there even such a thing as "blue?" What's real anymore??? Calm down — that idyllic scene just got way out of hand. We've got this.

Color Me Intrigued

A lot of people are colorblind to some extent — about 1 in 12 men and 1 in 200 women. And as you might expect, many of those people are walking around with no inkling that there might be something wrong with their color vision. If you spent your whole life thinking that the color green was a bit dull, well, it's not as if you can borrow somebody else's eyeballs to correct your mistake. You might not even realize it until somebody asks you to pass the gray bag and you pass the green one instead. Even if it is revealed that you see green differently than everyone else, you'll never know exactly what the non-dulled hue looks like. This all comes down to the idea of consciousness, which can't can't be shared between two individuals. Neither can color vision.

We're not just talking about people who have biological mutations that affect their color vision, though. The real question that we're asking is: Even if two people have perfectly functioning color vision, does each person experience the same color when they both look at an orange together? Obviously, both will answer in the affirmative if asked if the fruit is orange. But that's just a word, and if one grew up with a brain that transformed everything orange into the experience of blue, and vice-versa, there might never be a way to say for sure if you and your friend aren't as similar as you think. But new evidence is starting to seep in suggesting that maybe colors really are a highly individual experience.

Monkey See

Like colorblind humans — and most other mammals, actually — squirrel monkeys only have two types of cone cells, which are sensitive to blues and greens. As a result, the monkeys can pick out blue and yellow dots from a field of gray ones, but they can't tell red ones apart from green ones. Well, most of them can't. In a 2009 study to probe the limits of colorblindness, a few squirrel monkeys got an optical upgrade. They were infected with a genetically engineered virus that caused one specific, strange effect: It would randomly target green-sensitive cells and transform them into red-sensitive cells — a type of cell no squirrel monkey is wired to process.

But process it they did. The monkeys that received that particular mutation were quickly able to pick out all the red and green dots they wanted (there was a sip of juice in it for them if they got it right) — even though absolutely nothing had been done to their brains to give them a context for what "red" looks like. That's really weird. It's as if you were able to make the black-and-white film "It's a Wonderful Life" vividly technicolor just by playing it on a color TV. The monkeys' brains clearly adapted to this new type of information with ease — but what were they actually seeing? It almost certainly wasn't "red" the way you imagine it. As color vision scientist Joseph Carroll told LiveScience, "The ability to discriminate certain wavelengths arose out of the blue, so to speak — with the simple introduction of a new gene. Thus, the [brain] circuitry there simply takes in whatever information it has and then confers some sort of perception."

Here's the real kicker. There's no reason to think it's any different for humans with our three types of color-detecting optical cells. Every brain encounters blue, red, green, or puce for the first time at some point, and that's probably the same time that your brain decides on what the actual perception of that color is like. Here's Carroll again putting it in black and white, so to speak: "I think we can say for certain that people don't see the same colors."

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A scholar and a painter touch on the social, philosophical, and scientific aspects of colors in David Scott Kastan and Stephen Farthing's "On Color" (free when you're trying Audible for the first time). We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Written by Reuben Westmaas August 24, 2018

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