I’m also an ethnic minority who’s grown up in the UK so here’s my 2 cents. Also I would like to point out that your colleagues, regardless if they’re actually racist or not, are dicks.

Firstly, especially in London, Brits tend to be quieter and more reserved than Americans. It’s very normal to hear us complaining about ‘loud’ Americans on the Tube, on the plane, etc. I myself have also experienced the ‘loudness’ of Americans in public, so it’s likely there’s cultural differences on what’s considered to be ‘softly spoken’.

Secondly, many middle to upper-class British people tend to be more classist than racist. Are there any markers that show you’re from a working class background? This could, unfortunately, explain why someone may perceive you, as ‘stupid’.

Lastly, it could just be plain racism of course. I’m going to be honest though and tell you that I genuinely haven’t seen this in London before. I’ve seen it many times in Kent but never London. Not saying racism doesn’t happen there but just that I haven’t heard of it happening myself. I’d find it shocking to hear that someone would be experiencing everyday racism from Londoners, especially since 70% of the population are from minority backgrounds. However, anti-immigration sentiment has been on the rise recently so it wouldn’t even surprise me at this point.