It works, but you'll end up with a bit of a lack of contrast between the maple board neck and the pickguard (although better than a plain white guard). I doubt I will stick with the white pearloid in the long run - I'm contemplating vintage pearl for the added depth and beauty the celluloid has over the vinyl pearloid (it shrinks over the years, but then I'll make a new one).
BTW: A pic of the brown tortoise with black plastic. Overall, quite a dark combo.The burst isn't a standard burst though, it's a custom one I did for VV's Fernandes, specially to match the tortoise ?
You can also see how cream pickup covers and knobs would bring out the yellows in the pickguard.