I think, multi-cultural world like YLiakum have or had multikultural problems. Also he history mentioned it, for example the Ylian-Enkidukai conflict. An Enki who lost his parents or their farm and lifestyle because the Ylians build giant cities on the free hunt land doesn't like Ylan much, (AT least i used this in story once).
Of course we haven't call that all racism, but predjuices is a logical fact under 12 complet different races, especiall if soem have prefered cittis. For example, my Character Gohra grew up in a kran-only mining colony and never met any others before he came to hydlaa. So, he has no respect of different way of life. Especially a rivalism with dwarves is part of his background. But he is no racism because leading the Order o Light and learned to live with the others together in time.
What i asked were facts about interacial family problems, mix children often are under descission to follow the way of one parent and these can be different. For my short story i decided to use the Ynnwn version. The femlale borns a black skinned Diaboli and the dermorian father finds out that she betrayed him with a Diaboli lifeguard of his house. So he's unsure who's his children and finally he sent the young boy away, who grows up alone. Years later he's a head hunter without family, withou love in his heart. One day he gets a mission to kill a beautiful dermoian girl. He's on his way, what he doesn't know is it's his half-sister, an there the story begins...
Now i have he answers, if this is possible but i like this discussion, it's an interesting theme.