Subdividing color space (Score 1)

If you're trying to subdivide color space into n colors, where n colors are as "psychophysically" as separate as possible: Save most of the channel for brightness - our eyes can distinguish brightness/greyscale much better than hue or saturation. The psychophysical conversion for RGB to grayscale is .55*G + .33*R +.12* B - this means that green is twice as bright as red which is three times as bright as blue. It also means you should carve up your color sampling space similarly. Best psychophysical color space division I've ever seen is Apple's 256 color picker palette.