Color Theory, with Cats: Part 1

This was an unfin­ished draft meant to be published on April 3, 2010. Enjoy?

Je kunt beter over je fiets lullen dan over je lul fiet­sen.

–Dutch proverb.
Trans­la­tion: some­thing about bicy­cles and some untrans­lat­able stuff.

Color Theory, with Cats: Or How to Really Understand Color

Part 1 – Beyond RGB

Color theory is really complex. If you don’t think so, you are either some­body who doesn’t under­stand color or you’re a color scien­tist. Actu­ally, scratch that, you’d have to be a super­ge­nius color scien­tist (respekt), because the color scien­tists I know think color is complex too—and that’s not just an ego thing.

I real­ized that color theory was complex from the moment I acci­den­tally hit a button on an old computer moni­tor and had no idea what any of the menus meant. From then on, I’ve had a fine educa­tion in physics and computer science (if I say so myself) and I dabbled in psychol­ogy and biol­ogy with a bit of read­ing as well. Even so, I never really put all the pieces together until now. Now, I think I finally have a coher­ent model of how we perceive color from light.

So, it really grills my cheese to hear people talk­ing about just how simple color vision is. These range from regu­lar people who never have to deal with the specifics of image capture or color repro­duc­tion to art majors who insist that the universe is made from the color wheel to web design­ers who have no idea what they are talk­ing about: “Hey, you just have this hexa­dec­i­mal thing that ranges from 00 to FF and it repre­sents all the colors of the rain­bow! I’m so pro at comput­ers; Xo, allow me to teach you hexa­dec­i­mal numbers!”

On second thought, no web designer knows what he/she is talk­ing about, so that was a bad exam­ple.

Nonethe­less, color igno­rance (not to be confused with color­blind­ness) grills my cheese so much that I have to look at pictures of kittens when I think about all those people living in fear of the truth. In fact, it moti­vated me to write this series of arti­cles on really under­stand­ing color—in Geor­gia spring­time with a cat sleep­ing next to me:

And I can still feel my blood boil­ing a little when I think of the people who would say things like:

  • “If you combine red, green, and blue, you can get all the colors of the rain­bow!”
  • “The spec­trum has every color visi­ble to human eyes!”
  • “Octarine is the eighth color1!”

Look, my cheese just gets really grilled on this one, OK? I mean, just think of what a wide­spread under­stand­ing of color would do to progress racial equal­ity!

But I digress. Here’s your damn arti­cle. With cats.


I will be using numer­ous gener­al­iza­tions and assump­tions in this part of the series; for a more in-depth look into specific topics, see the later parts of this arti­cle. Let’s start the gener­al­iza­tions of color with the thing that lets us see color: light.

With­out specifics with respect to quan­tum mechan­ics et al, light is elec­tro­mag­netic radi­a­tion that we humans can see. As you learn from any physics class, light is both a wave and a particle—it can do all of the funky things waves can do, like reflect off of mirrors or refract through lens, as well as all the things parti­cles can do, like being easy to under­stand.

For the sake of this arti­cle, we’re going to think of light as parti­cles. Light parti­cles are usually known as photons, and can be visu­al­ized as little pack­ets of energy that each have a direc­tion and a speed. The speed is pretty much the same for all of them, and tends to be the speed of light c (not to be confused with my friend GS’s C, which is the stocker ticker for Citi­group).

This is a good way to visu­al­ize a collec­tion of photons moving in roughly the same direc­tion:

Except this arti­cle is called “Color Theory, with Cats,” not “Color Theory, with No Cats at All,” so here’s a better way to think of them:

This picture would be accu­rate if you just keep in mind that photons occupy no space at all, but are instead purely energy. That’s why they move so fast, and also why you can’t hear sunlight meow­ing.

a哦iha­sof­pouheuh哦哦ijoioimkjhooph oia jodhwaiu

  1. Ed: After receiv­ing numer­ous correc­tions on this point, I’d like to point out that “octarine” is indeed the “eighth color,” what­ever that means. []