I am White English, but I do remember my dad explaining what happened after World War 2.
If I remember rightly, he explained that due to the war, there was a massive shortage of labour for mainly meanial jobs in the UK. Consequently, Jamaicans, Wests Indians etc not living in the UK, (but I think think part of the then British Empire) were invited to take up those jobs. Consequently we had a flood of Black people coming to this country. That was very eveident, where I lived in Birmingham as a lad. They settled in principle very well into the community and indeed I played cricket with a lot of the children of those families that came here. I even went to their parties, which were great fun. However, they always thought that I was from the police and the same with my white cricket mates LOL
So 60 years on, they have certainly become an intergral part of the Midlands.

Unfortunately, I am unable to find anything to substantiate the above as my father is no longer alive.