Train yourself to see impossible colors

(VIA)gizmodo.com

Hiding in the shadows between the colors we see everyday are weird, impossible shades, colors that you shouldn’t be able to see and generally don’t…unless you know how. Here’s a simple guide to seeing impossible and imaginary colors.

Image by Cody James.

Understanding a little about how humans perceive color is crucial to seeing impossible colors. Our eyes use something called opponent process to work more efficiently. This plays upon the fact that the eye’s primary light receptors, the cones, have certain overlaps in what light wavelengths they can perceive. To save energy, our eyes measure the differences between the responses of various cones rather than figuring out each cone’s individual response.

We long ago found out that there are three opponent channels: red vs. green, blue vs. yellow, and black vs. white. (Technically, black and white aren’t colors, and their opponent process has more to do with brightness than anything else.) Now, let’s say you stare right at the bluest object you’ve ever seen. Your cones that primary perceive the blue wavelengths are going to be excited, while the cones responsible for yellow will be inhibited. If you then switched to looking at the yellowest thing you’ve ever seen, the exact opposite would happen.

It probably isn’t all that shocking to point out the cones can’t be excited and inhibited at the same time. That means that it’s impossible to see an object that’s simultaneously blue and yellow or red and green. I’m not talking about what happens when you mix those colors and then look at them – obviously, you’d get green and a sort of murky brown if you did that. No, what I’m talking about here are colors that are equal parts blue and yellow at the exact same time. Can you imagine that? Well, you shouldn’t be able to, because that’s an impossible color.

This might all seem a bit abstract, but there’s some evidence backing up the existence of such colors. A 1983 experiment featured a special machine which separated the fields of vision of the test subject’s eyes. One eye would see a red screen, while the other would see a green screen. Given time, the colors would mix together, but the mixing only occurred in the brain. Without the eye there to mediate the mixing, red and green didn’t become brown – they became a new color, a reddish-green color that none of the test subjects had ever seen before, and that includes an artist with an extensive knowledge of different hues and shades.

READ MORE HERE