People voted Brexit for many reason, Strolls. Control of borders was central one, and from what I've seen, there were two aspects to this. First, security, in view of some horrific attacks in Continental Europe with terrorists moving with impunity around the Schengen Area, and Mrs Merkel taking in 1 million immigrants, mostly male and Middle Eastern/ North African, without any form of vetting. Second, the huge numbers of immigrants coming into the UK (a city the size of Birmingham every couple of years).
The British are among the least racist citizens in the world (compare our attitude to members of the EU in Eastern Europe eg Hungary). Huge numbers of immigrants have been accepted into the UK in the last 50 years. In the north of England, whole towns have been taken over by immigrants. More than a third of the population in London is foreign born. This century, Blair's government decided no cap was necessary on immigration after the former communist block countries joined the EU, and huge numbers came in, far, far greater than Blair predicted. Still, only a small group of extreme right-wing headbangers march on the grounds of race. The average British family is simply concerned about the pressure on services. They want their children to be able to find a place at nearby schools and afterwards, find a house to live in nearby. They want to be able to get to work simply, without queuing on choked up roads. They want an appointment for a doctor earlier than 5 weeks. etc... It's not racism. Nor is it racist to discuss problems that mass immigration (as opposed to simple, controlled immigration) have brought, despite the fact that the Far Left are continually trying to shut down debate and no-platform speakers with whom they disagree.
And only the sprinkling of right-wing headbangers would argue that after Brexit, no immigration should take place. Some fabulous people have emigrated to the UK. Immigration simply needs to be controlled now, that's all. And by the British Parliament, not unelected bureaucrats in Brussels.