Board Thread:Naruto Discussions/@comment-25369463-20141001042907/@comment-4912646-20141002010921

I was under the impression that Obito's hair turned white because he overexerted himself sealing the Ten-Tails, since his hair changed before the sealing actually started. On the other hand, Madara was able to seal it effortlessly and in a matter of seconds, without any indication of exerting himself, hence his hair didn't permanently change.

Doesn't explain Madara's peeling skin and disappearing cracks while he was controlling Obito though. It's not like those effects were only added for the reader's sake either, since Hashirama seemed to notice Madara changing.