Turns out this penguin probably has a condition called melanism that is rare but not unheard of for penguins. It seems this one has been around for a few years and thus doesn't seem to have suffered much. In the pictures he looks decently plump. Most other penguins with the condition will have dark splotches but their color won't be completely altered.
We here at ASOC wish him all the best. It's always awkward to be the one person at the party not in formal wear.