> Pick any three musical notes, even on a microtonal scale, and they form a pleasing chord.

I cannot speak to the color part, but the music part doesn't ring true to me (pun intended). For example, if I pick the first, the second and the seventh of the Phyrigian scale, it sounds pretty jarring to me (like, playing E, F, and D at the same time). And, this is staying pretty much within the scales in western classical music (although I doubt anybody would play it, I bet somebody made it context). Also, extended chords with > 3 notes sound pretty fun and has been the staple of western music for a while (blues, jazz for easy-to-reach examples).