Guangzhou has a very visible African minority population, probably the largest of any mainland city. China like the rest of Asia is super colorist, and there's a lot of inter-ethnic developing world one-upmanship that goes on. So yes, many Han Chinese people are uncriticly racist--but not to the same systemic level in any way towards black people as what we see in the US. Anecdotally, black people often have wildly different experiences travelling in China, and often have the feeling of being treated more as a foreigner than as a black person, if you get what I mean.