It turns out, of course, that all those gleaming white statues were vibrantly colored back when their creators were around, and the Greeks and Romans were not cultures of conformity or austerity - quite the opposite, but the seeds of the philosophy sank in hard, and here we are.
(Ironically, both stoicism and Christian asceticism were responses to that Roman excess, but they've somehow been merged with the white marble to produce a "purity" aesthetic to be lionized whenever someone gets the mildly uncomfortable notion that their neighbor is not exactly like them.)