From the character of Islam, its egalitarian set up, it is clear that there is no racism in Islam. If father is African, mother Caucasian and the children somewhere in between then it is perfectly normal Muslim family. When beloved Prophet said at the time of last pilgrimage that there is no preference of Arabs over non-Arabs then all racism was thrown out of window - if there was any doubt at all. And this latter possibility was not there because he was addressing the honourable Companions (RA) - I suppose above words were for the benefit of us miserable people.