https://twitter.com/warcraftdevs/sta...48605922082816 I'm slightly surprised no one posted this but, most are aware now of how, if you have the alternate colors unlocked on a hidden appearance you do have, you can use that color tint on a hidden appearance you do not have. And many use this because some hidden appearances are stupid hard to obtain through rng.
Well, the above tweet shows they know it's a bug and they are not going to fix it. So people who are relying on this ability can rest easy that it's not going away.