Where the rainbow gets complicated

By Britta Gustafson

On Monday I talked about different kinds of insect art: creepy-crawly and odd but good. Today I have a bunch of links about a few aspects of color vision that I think are cool: How many colors can people see and distinguish between? What happens if you have eyes that see colors differently from normal? What alternate ways are there to think about color?

A recent article in the New York Times discussed deer vision research that went into developing hunting camouflage — for example, “[deer] have a hard time seeing blaze orange,” which is kind of lucky because humans use it intentionally as a color that’s easy for us to see.

You can test your own color distinguishing abilities with the Farnsworth-Munsell 100 hue test, where you try to arrange little colored blocks into the correct gradient order. I first heard about the test when I read an article about whether wearing tinted contact lenses can impact your color perception. Another color distinguishing experiment is a Flickr set of colored objects with appropriate Pantone color chips attached to them, as decided by a machine. There’s a complex history behind Pantone and color organization systems, and much to discuss about models of human vision in software, but those are stories for another day.

Vischeck has a neat free tool where it simulates certain kinds of colorblindness by providing images of modified-color websites. People with normal color vision can use Vischeck to experience approximations of deuteranope, protanope, and tritanope color vision, but a couple colorblind people I know have had even more fun with it, testing out the simulation of their type (and seeing if the result looks just like the “normal” webpage does), trying the options for other kinds of colorblindness, etc. A few people may have an extra ability to distinguish between colors, as explained by an article titled “Looking for Madam Tetrachromat”: “Most of us have color vision based on three channels” but a certain genetic mutation could provide four channels.

That’s mind-bending already, but I have two more favorite color-related thought experiments. Squant is a “newly discovered primary color” with a whole website describing the ramifications of such a discovery. I don’t even know how to explain the second one — you’ll just have to read the Wikipedia article about grue and bleen and try to wrap your head around it. That article also links to another titled “Distinguishing blue from green in language,” which is a good entry point into thinking about color distinctions as culturally constructed (and somewhat arbitrary) concepts. But I probably just scared off all the non-humanities majors so I’ll stop there.