Answer by Todd Allen:
I actually was in this scenario.
I was a shift lead for a restaurant when I was 18 or so. An employee got me since a customer had asked to see management. The customer was an older guy, very nicely dressed and soft-spoken.
For such an inherently obnoxious request, he made it in the quietest way possible. He said that he would "prefer that the coloreds don't touch my food". I remember it quite exactly, because it was just so shocking.
I told him I'd need to get our general manager, and would be right back. He seemed quite satisfied with that. I was, too.
I went to get our general manager, John*. John was generally very mellow, and like any restaurant manager, he'd dealt with some very troublesome customers in his time. He was generally good at it.
John was also a very large man. And very black.
I accompanied him back to the man, whose eyes were already wide. I introduced John and asked if he could repeat his request. He didn't seem to want to do that, so in the interest of being helpful, of course, I restated it. John's eyes got a bit wide, but he just quietly said "Well, sir, if that's what you want, I think you're in the wrong place." The guy apparently agreed, since he left in quite a hurry.
So, certainly, there's no need to get obnoxious or violent oneself. But that doesn't mean the request should be honored. That's one case where the customer is certainly not right.
(not real name)