Martin, have you watched any of Prof. Gates's series on PBS about genealogy? (Henry Louis Gates, 'Finding Your Roots.') I sometimes find him and his mannerisms and condescension annoying, but the photos and history are interesting, and the series brings up issues that it's probably good to be aware of.
The latest (rerun) episode had three people who identified as black but had lighter skin colors and, as it turned out, some degree of mixed heritage. (Bryant Gumbel, Suzanne Malveaux, Tonya Lewis Lee.) He has also had people with Asian and other ancestral mixes on in the past. https://www.kqed.org/tv/programs/index.jsp?pg...
And apparently, one thing that they often have in common is that in public, people do indeed feel free to ask them leading personal questions that, as Dr. Gates summarized it, boil down to just 'What are
you exactly?' Which is actually kind of a rude thing to ask, precisely because it just reemphasizes the unspoken assumption '... because you don't quite look like the rest of us.'
I agree that most such questions aren't intended to be racist or demeaning. They can arise out of simply wanting to know someone better, and starting with a topic of conversation that seems like an easy icebreaker. But as with any kind of personal question, it can come across as intrusive, or intended to serve to place people in a box, a category. Questions like 'Where are you from originally?' can come across as meaning '... because you don't look/sound like you're from around here'; questions like 'What do you do?' can come across as meaning '... because most of us are defined by our jobs.'
And you can understand that for people with unusual names or appearances, being asked the same question by practically everyone they meet can be wearing, over the years, just like very tall people are not likely to be enchanted by comments like 'How's the weather up there?', and disabled people are not likely to want to explain to every new acquaintance how they came to use a wheelchair.
At the same time, unless people are willing to talk about their heritage to some extent, it kind of suppresses our awareness of all the interesting ways we came to be the different group of people that we are. So in a sense, I hope people in various minority categories will be patient and sometimes just answer questions, to help educate the rest of us.