I think most asian countries have words to describe foreigners.
In Japan it's gaijin. Heard with equal frequency as farang in Thailand.

It's a result of living in a very homogeneous society. It's what sets them apart from us and is immediately obvious.

If you owned a hardware store in Bournemouth and some purple guy with five eyes walked in and asked for a light bulb, you'd probably run to the back and tell your co-worker to come look at the psycho motherf***er who just walked in.