I read with interest the article American and Japanese cultural misunderstandings in communication, in which the white woman in Japan realizes that the rejection she initially attributed to racism was actually due to communications issues.
It reminds me of experiences of African expatriates in Singapore. Some individuals experienced reactions clearly rooted in bigotry - such as one local woman holding her nose when walking past an African man on the *other* side of the street. Other experiences were more subtle, such as maybe, an empty seat next to an African man on a crowded bus and no one is taking it. My first reaction, as someone who has experienced discrimination even when I've approached social situations with an open mind and assumed initially that I would be taken at face value, was to think that was because people were racist and did not want to sit next to an individual of African descent. Then I started paying attention to other empty seats on buses. I noticed that when people choose which empty seat to take, they usually go for a seat next to a child, or a small adult, if one is available. My guess is that they figure if the person they're sitting next to is smaller, they will have more room for themselves. So a big foreigner might not be the first choice for someone they'll sit next to, and the motivating factor might not be race, but rather, size.
I also talked to another foreigner, a woman from China, who observed exactly the same phenomenon - that is, an empty seat next to her on the bus, and no one taking it. But she did not attribute it to racism since she wasn't expecting racism (the majority of Singaporeans are of Chinese descent). She concluded that Singaporeans did not like to sit in recently-vacated seats warmed by other people's butts (regardless of race). Or maybe some people want to stand a bit after sitting a full day at the office.
So we have two foreigners seeing the same thing, but interpreting it differently, based on their own previous experiences and current expectations. Not to deny that there is racism in Singapore, as there is anywhere else. But I think, sometimes, if we go into a new place expecting 'racism', then we'll start to read 'racism' into situations even when it really isn't there. Anyway, since then, I have noticed buses with empty seats and people standing around, ignoring those empty seats, and those empty seats were next to locals!