The Chinese attitude towards Africans and their overseas descendants is very well known to anyone who pays attention.
Not just against white or blacks but against other Asian groups as well.
My MIL is from Thailand--I have heard it all from her and her friends. "Dirty Laos" "Dirty Cambodians" "White sluts" "Criminal Vietnamese" "Jayboojiggaboo" when referring to blacks. They let the N word fly like they are saying the word "hello".
I have been shopping with her and watch her peruse the cashiers and if there is an Asian cashier, that's where she goes. Because even a "dirty Cambodian" cashier out ranks a white or black one.
Disclaimer: she is crazy also.