From black faced to purple faced in the anime.
Jynx was in fact black-skinned in the Red & Blue days. But due to its skincolor and human-like shape, it was considered racial towards black-skinned. The original Jynx episode was banned, and GameFreak changed Jynx apperence.
Some say that Jynx was really a racial appearance from it's black face in original games. So I guess that they changed it? Maybe or it was supposed to be purple after all I think.