It is a sticky situation. You have to be so careful what you ask and how you ask it. As a genealogist, I am always interested in a person's ethnicity when I encounter an unusual name. But I always explain that I am interested in genealogy and ask about the background of their name. Perhaps I better stop doing that. For what it's worth, I don't think I have ever asked that of people of any color. Well maybe Asian or Pacific Islanders.