We humans (myself included) seem to gravitate to almost luridly colorful displays that let a hundred colors bloom, as Mao might have put it. Not surprisingly, rainbow colors have become internationally symbolic of inclusiveness. Ironically, what we see as a color is the color something is NOT, of course; so much of the natural world is green because the largest part of the solar spectrum is green, and sunlight is powerful enough to cause damage for unprotected organisms.