Illegal, this is? Whatever happened to "we reserve the right to refuse service to anyone"?
Personally, I would be the first one in line at a restaurant that served whites only, or upper class people only, including affluent blacks who behaved in such a way as to be considered stereotypically "white", i.e., they tip, they don't speak loudly in ghetto slang, and they're not rude to the help. That would make them "oreos", correct?
There was a lawsuit against Denny's, not too many years ago, for not seating blacks, and I felt that this particular Denny's was justified. Any waiter or waitress can tell you that, in general, and without regard to any specific individual, black people just don't tip, and they demand more service. If black people want to be taken seriously and seated at a restaurant, they can tip like everyone else does.