I'm not mixed myself, so I might not be the best person to comment, but I've grown up around tons of mixed people and it's really common around here.
My best friend growing up was half black / half white and we talked about discrimination and racism growing up, but it was all in concept, it was nothing that ever touched us.
I don't think he ever faced any kind of discrimination because of it back then.
Another friend I grew up with is half-turkish / half-german (not exactly mixed-race obv.), people mostly seem to think she's french and like her slightly 'exotic' look. Again, i don't think she's ever faced any sort of trouble because of it.
Now, I'm not so sure though, germany used to be devided and there's a big problem with racism and xenophobia, predominently in the ex-GDR states and it is emboldening every washed-up racist that had been hiding under the surface before, even in the rest of germany.
My mom is a kindergarden teacher and they have kids with parents from ex-GDR regions that refuse to play with the black kids, or refuse to touch black dolls and call them 'disgusting'. We're talking 4-year olds here, so they are definitely getting this stuff from their parents.
It just makes me really sad that even small kids get indoctrinated with hateful stuff like that. At my moms work they do their best to contradict those statements gently (aka. asking 'why do you think it's disgusting?', making them think about it instead of just repeating what they hear at home) and do projects about multiculturalism, cultures in the world and acceptance and tolerance, trying to show them their diffrences are interesting and that they probably have more similarities than diffrences anyways.
I also heard an old man screaming obceneties at some black people walking by the other day and that was literally the first time in my entire life I've seen something like that happen here. I got angry with him and shouted back, because he was being despicable, but the fact that he even dared to do that at all seems really bad to me.
Overall I think that in my Area these kinds of incidents are thankfully still very rare, and overall acceptance is good, but the rise of nationalistic, racist and xenophobic tendicies is definitely worrying to me.
