Racism in the UK

I think theres a fine line between racist remarks and a joke....people take so many things way to personally

Right, now I don't mean cities like London where there's a huge mix etc. but generally in the UK where cities are majority white, I always sense racism towards me. I'm not saying everyone who is white is racist, but I do see it happening. People try to be politically correct, and embrace other cultures etc. but sometimes the racism is so blatant, like a cashier would smile at every white customer, but not at the Arab. Although he isn't being racist, as an Arab I always feel that I'm looked down upon. Now there are some people who have no problem with me being Arab, my girlfriend who is white actually first started to like me because I looked exotic to her. Anyway, I was wondering if anyone else has noticed this, and what your opinions are?