Portugal was the first to get all into the black slavery business, and Negro does happen to mean "dark" in Portuguese...
... Which, when I think about it, is all the more reason that this would be possible; keep being called what the first European slavers named you, or get a new name?
The New Orleans Negros starting off as an All-Afro team?
That's beautiful. However I don't imagine Negro getting some of the connotations- after all, Voodoo is in no way a superhero's power. So I guess New Orleans will have to go for the name no one else wants.