Really depends on the skin color of the person visiting and where they are visiting in that country. A non-white visiting most West-European cities will be mostly fine, but if they go out to the country-side, things can be very different.

I watched a documentary of an Indian boy adopted to a Swiss family who then went back to India to visit. He had a terrible time in Switzerland due to racism and nearly as an awful time in India, because he couldn’t speak the language and people thus assumed he was a Pakistani spy.