Without challenging any of the points made, I may safely say that one of the pleasantest and competent captains I flew with as FO was ethnically African. He went on to management in a major national airline. He used to post on Prune but haven't seen him for about five years.
In the Far East, we had a black chief training captain in a predominantly white sister airline.
Please don't think I'm 'virtue signalling'; if I had something adverse to say, I'd be equally happy to spout.