Tangential, but does anyone else see movement near center of the color wheel when changing focus away from it? Optical illusions fascinate me. Are certain types categorized?
No, I didn't notice the movement you describe. But the color wheel's content appears to grow and shrink the slightest bit when I move my head towards it and away from it, respectively. Probably a halo effect.
Hue is the color wheel. Once you know that a hue of 30 is orange, you immediately know that a hue of 30+180=210 is blue, since it's across from orange on the color wheel.
How much time have you spent fiddling with RGB values to pick colors? I assume it's either a lot less or a lot more than me, because while I too can certainly imagine what any given mix would be, my imagination is usually so far off from the real result as to be useless.
This has been true even when I worked in pure gray. 50% each of R, G, and B results in a perceptually very dark gray (that is, the contrast between #808080 and pure black, #000, is much less than the contrast between #808080 and pure white, #fff).
Elsewhere in this thread I sang the praises of HCL, a color model where you can adjust independently the hue ("color" in the traditional sense, as in orange vs blue vs yellow vs green vs red), the perceived brightness, and the perceived "grayness" (saturation) of a color: http://vis4.net/blog/posts/avoid-equidistant-hsv-colors/
More important than knowing "hue 30 == orange" is the fact that one can decompose the color to "The hue of this color is orange". Then, finding orange on a color wheel is not so difficult. Especially if you can put in appropriate values for saturation and luminosity.
So, regardless of whether or not you know the exact hue value of a given color, it still decomposes more easily than RGB :)
TIL hue is almost like an index of color. I guess a hue of 30 will always be orange. The conical conversion method between RGB & HSL is a little amazing.
At least with RGB, I can imagine what the mix would be.