Well, maybe not if you’re Joe the plumb bob, but if you’re an illustrator, designer, or prepresser (what’s the feminine form, prepresstress?) it does. I came across another little paper the other day that I used to use for Photoshop training, and like the blend mode diagram, I offer it up here for your use.
This color wheel shows the relationship between CMYK and RGB colors, and has a handy dandy mnemonic for remembering the correct order of the colors:
Bad color gets you really mad. Blue cyan green yellow red magenta.
So how can this diagram help you in understanding those RGB and CMYK color models? Or more practically speaking, how does it help you color correct? Simply put, the components of a color are those that are adjacent to it. To make red, you add magenta and yellow, to make blue you mix magenta and cyan, to make green you mix cyan and yellow. That’s pretty obvious, even to a crayon-wielding 1st grader (I surveyed one at home last night).
But what might not be so obvious is that when you’re working in an additive color model, like RGB, green + red = yellow. Red + blue = magenta. And blue + green = cyan. Don’t believe me? In Photoshop, make two layers. Fill one with pure green (0r255g0b) and fill the other with pure red (255r0g0b). Now set whichever layer is on top to the Screen blending mode (which adds the brightness of the two colors).
Or you could do the old flashlight trick. Take two flashlights, cover the lights with colored cellophane, shine the two together. Be amazed. Actually it makes total sense. Light + light = brighter light, right? Right. In my house we use our make-your-own lightsaber kit, which comes with perfect translucent plastic circles. Cyan for Jedi, red for Sith. Opposites. Managed, your color is.
The other thing this diagram can teach you is how a subtractive color model works. In a subtractive color model like CMYK, the ink or (crayon wax) subtracts some of the light that passes through it before that light bounces up to your eyeballs. What part of the light does it subtract? The color that is opposite on the diagram. Need another mnemonic? How about Opposites Subtract? A blue crayon mark subtracts yellow light. That’s how it makes the picture bluer. And it works the same in Photoshop as it does in Crayola. When you’re in the Curves dialog box and don’t know whether to pull that Blue curve up or down, keep the Info panel open, and think of this diagram. More blue = less yellow. Less blue = more yellow. Too much cyan? Up the red. And so on. You can see this illustrated in the the Variations dialog as well. Those previews aren’t arranged randomly. They follow the same order as my “Bad Color” diagram.
Master that color wheel and you’ll be saying, “Beautiful color! Gosh, you rock, Mike!”