Two posts and you joined yesterday. I don't mean to lean on arguments from authority, but I think you might be catfishing and strawmanning. So perhaps you can add some realm/unit info.

Black-face is offensive because it was used to perpetuate stereotypes. A classic example of The Birth of a Nation is an actor in blackface portraying all black men as slavering beasts. Unless you'd care to argue or expound on that point.

To be honest, I don't know anyone who wears native garb who doesn't at least claim to be descended from a Cherokee princess. The person who I can think most clearly as wearing native garb is Apache/Sioux. Who are you to presuppose their rights to such garb?

Now maybe dressing like an Iroquois extra from the Last Mohican is out of place. But that'd be no worse than a Danish/Scottish guy (myself) dressing like a Roman.