Besides this evidence, I can only bring up an example I've mentioned before. In a novel by Norah Lofts (sorry I can't remember the title) someone advises the heroine "You need not worry about an enemy who turns red with anger, but beware of one who turns white with anger, for s/he will make a formidable opponent." Somehow, even up to this point in the book, Darcy strikes me as a more formidable person in general than Wickham does!