Hollywood has a long history of miscasting whites as Indians. Some worked; some didn't. Two who I thought turned in credible roles as Indians were Jeff Chandler as Cochise in "Broken Arrow" and Sal Mineo as Red Shirt in "Cheyenne Autumn". But Howard Keel, who just died of colon cancer at the age of 85, wasn't believable as Levi Walking Bear in "The War Wagon". He played the role pretty much tongue-in-cheek but then, so did some of the others in that film.
My favorite Keel role was as Wild Bill Hickok in the Doris Day vehicle "Calamity Jane". Anyway, rest in peace, Howard.