It happened when I was looking for an art exhibit opening ("Dinkelaka") in Stuttgart... I was guided to the place by a mother and daughter who noticed that I was looking at directions I'd printed out from the internet.
The daughter approached me first. She looked black. The mother, who looked white, later explained. Her husband was African, and she was Italian.
(I'd noticed the relationship between the girl and woman, as we rode together in an elevator up from the u-bahn (subway), and it seemed as if they were mother and daughter.)
When I told them I was from the US, the mother said that her husband had often spoke of emigrating there. He felt he could have a better chance of advancing his career, than in Germany. The Germans, she said, tend to stick to one another, so there was little opportunity for her husband to move up. (Of course, the terms we use to describe this phenomenon in the US are glass ceiling and discrimination.)
I think this sort of thing may be overcome, but it may take a generation. Perhaps the daughter may be able to benefit from the social change, but will she want to remain in Germany, by that time? Will she still want to live, there?