There was definitely racism, though at that point in time, there wasn't any racism enshrined in law (though some laws did come about over a decade later regarding immigration from non-white parts of the commonwealth) however there was no protections from racism. Racism in Britain was very much on a case by case basis and while I don't want to diminish how it was in the early 40s, it was considerably worse come the 50s as a reaction to several large waves off immigration (which were also spread across more cities than previous waves) which also turned racism into a domestic political issue.