Black people did nothing to God. Their persecution by Europeans (including European-Americans), Arabs, and others isn't due to God, but rather is the result of human greed and malice.
European-Americans in the USA have been particularly fond of justifying their persecution of black people by pretending that all black people were cursed by Noah, and although Noah was just a man (not divine), his curse somehow made it God's will that others should enslave and persecute all black people. Of course, that nonsense is transparently a contrived excuse and camouflage - but it can STILL be heard in some quarters in the USA to this day!
If you want to understand the origin of the persecution of black people in a scriptural setting, it stems from SIN, not from God. From Satan, if you will.