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. []