As with form, if done correctly, color shouldn't distract nor harm a piece. Over time no end of materials have been painted as mentioned... da Vinci on wood, Michelangelo -the Sistine Chapel ceiling .. was it they'd had nothing else, no it had to be painted. Wilma, no doubt told Fred to paint animals on the cave wall to make it homely and remind him what he should be hunting... it was a ready material ... where he got the paint !!!!!!
Stained glass windows .. do they add/distract from the Light or the glass itself...
It's a case of the right balance, is it just in coloring wood, need we consider texturing... in the end beauty is in the wood itself .. then we have bland pieces, so what's the next better thing to do.
Cheers David