Schools should do more to encourage integration to stop the UK sleepwalking its way to racial segregation, race equality chief Trevor Phillips says.
Schools are the starting point for better integration, it is suggested
The Commission for Racial Equality head warned the country's increasingly segregated schools were "schooling people to be strangers to each other".
He suggested "creative" solutions such as changing school catchment areas.
Labour peer Lord Ahmed said the comments were "insensitive" and did not reflect life in much of Britain.
In an interview with Radio 4's Today programme, Mr Phillips said ethnic segregation in the UK was "reaching US levels".
He said schools should be leading the way in terms of integration but research had shown they were in fact slightly more segregated than their wider neighbourhoods.
Mr Phillips said it "cannot be right" that in a borough with a 30 to 40% ethnic minority population, there might be some schools with 95% minority pupils and others with just 2%.
And he is warning some universities are now effectively "colour coded".
He told BBC News: "Let's say in our best universities, people who come from ethnic minority backgrounds walk onto the campus, they look around, don't see anyone who looks like themselves and they think, 'Aha.' What do you expect them to do. They're not going to choose to go to those places."
He rejected the idea of positive discrimination in education or quotas to ensure diversity.
But he said: "We can find creative solutions to this, maybe look at the way we draw catchment areas, maybe combining sixth forms at some point."
Mr Phillips warns of 'colour-coded' schools and universities
And he said his organisation was investing £2m in organising integrated sport activities to help people "get to know each other".
He said: "It's one way people can meet each other, know each other, they don't have to love each other or even like each other but we think if we at least know each other, that is the fundamental platform for a better, more integrated society."
Mr Phillips was speaking ahead of a controversial speech he is expected to make to the Manchester Council for Community Relations, voicing fears that Britain could be drifting towards "New Orleans-style" racial divides.
He told BBC News: "We have now done some research which shows that we are not making friends across the colour line. When we leave work, we leave multi-ethnic Britain behind.
"We are going in the wrong direction. Our worry is this, that this is fertile breeding ground for extremists.
"As in the United States, you can get to a point where actually things are so divided, there is no turning back."
Liberal Democrat MP Dr Evan Harris said it was "sheer lunacy" that the government was establishing more faith schools, which would segregate children on the grounds of religion and "effectively therefore their race".
He said: "What we can and must do is to insist that schools don't discriminate and segregate."
Lord Ahmed told BBC News Mr Phillips' "headline grabbing" comments were badly timed, coinciding with a report by a taskforce set up by the government to investigate ways of dealing with Islamic extremism.
He said: "I think that Trevor Phillips has been insensitive to start a debate when the Muslim community is facing one of its biggest challenges in fifty years."
He added: "I don't think Trevor Phillips visits much of the United Kingdom outside the M25.
"I live in the north and I travel in the north every weekend. I travel around the country and I see many, many very good examples of communities living together very happily and they're very successful."
Mohammed Shafiq, of the Liberal Democrats' Muslim Forum, also disagreed with Mr Phillips, saying multi-culturalism was a success.
Speaking at the Lib Dems' party conference, Mr Shafiq said Mr Phillips' comments were "inflammatory and offensive" and called for him to resign.