I was reading a book and it mentioned a study where the researchers found out that people will always try and find a reason to dislike the "other guys". They will even use the language or eating habits of the other group as a reason to dislike them or feel that they are a threat. Based on my time travelling to a few places in Europe and North America and talking to a few relatives who travel, London is a pretty chill location. I've been to places in Italy(Sicily) and I couldn't go a day without some ignorant old or middle aged guy looking at me with anger in his eyes just because I am black and he has his preconceived notions despite the fact he doesn't realise I come from a long line of successful black men and women. At one point I just paid and left my food at a cafe because I was too angry and I had never witnessed such ignorance.The same shop owner (who's water bill and house bill I just paid for with my money) was staring at me in anger through my whole time in his place of business. I felt like those black guys in those old American films who would walk into a cafe and are welcomed by daggers from multiple eyes.
Based on my little experiences and my observations, I think you'll be more than fine in most parts of London. People are more open minded than in many other places around the world when it comes to race. I studied in London for my undergrad and it was fantastic. There are racists everywhere but I feel like some more advanced locations, if racist, make it subtle. So, even if you come across racists in London, you probably won't realise till later on when you are a seasoned veteran lol. London is a place where you can gain respect based on your character. Many people have interracial relationships there even. Even many other parts of UK seem to be used to the idea of having foreigners around. Sure, there may be people who are not openly racist and there may be some who are but there will always(at least for now) be racism everywhere . I think when it becomes more dangerous is when people refuse to open their minds to the possibility that you may be judged on your character.
So I guess really, it just depends on the location and how intense the racial discrimination is.Also, it depends on age, family upbringing , and etc. I'm certain not everyone in Sicily is racist. I met some of the most incredible people I have ever met in my life and I met girls who just wanted to know me because I am black (although that may be racist in itself). Even if a location has a lot of racism, it doesn't necessarily mean you will have the worst time of your life as there may certainly be people who aren't ignorant or foolish. As I understand, there are even some(probably 0.5 %) African professors in India . My dad even used to go there for business trips so I doubt it's all doom and gloom.