Its more ignorance than actual racisms I think. I had a local hiking friend who was going to move to the UK and wanted some "tips" on getting on in the UK. We go onto the subject of black people, and he was stunned to hear that assuming a black person in the UK was an African expat might not go down too well.... He just thought all black people come from Africa. How anyone can think that given all the "black lives matter" news or that the USA has a black president or ..... but this guy, reasonably well educated, just didn't think about the rest of the world much and thus had no idea about such things.