Y'all remember Juanita Hall, who played the Polynesian vendor, Bloody Mary, in "South Pacific" and the Chinese aunt in "Flower Drum Song"? I found out a couple of years ago that she was black!
Once you know it and really look at her in those movies, you can tell but most people don't pick up on it! I read a biography about her--she was a famous gospel singer in her own right. What a great voice!