Progress!!
Since the octave has 12 tones, and the color wheel has =12= tertiary colors,
I'm gonna use STRAIGHT PHYSICS to map em

But tonic of key always starts at red. 5th is always cyan-ish blue.
It's not gonna use the solfege or boomwhackers color map, cuz, eh, sorry,
their mappings have errors.
Although, mmm, they are WAY more popular than mine.
I'll probably have to make that customizable eventually...
Here's how it looks: (oooooooo, pretty - gaaaaaah:)
http://pianocheater.com/etc/colorz.png(make sure it's expanded to actual full size)
Little lines show down the "page" which of the white/black keys are
WHAT scale spot.
Starts on red=tonic, green=mediant(or M3rd or whatever), dominant=green.
finishes on pink (leading tone). Repeats on next octave, etc.
tonic bass'd major chord shown on keyboard here.
(this is part of the Beatles' "Let It Be".)
Does this look good to you?
It looks kinda WAY too busy to me,
but I'm gonna see if it grows on me...
Eventually, on modulations (or any key/scale change),
you'll see the colors shift over to the new key.
So when you go from c major to a minor,
M on c keys would change to m on a keys.
and you'ld see the new minor scale with the lines.
(red lines move to a keys)
and minor specific keys would be their special minor color.
the flat 3rd, etc.
I'm very interested in what a piano TEACHER thinks of this...
I'm too much of a newb...