Sure enough, one child after another expressed views which indicated that whatever their backgrounds, they all thought that white was better than black. The children who moved me most were those who came from mixed- race families. Serena, for example, had clearly thought a lot about this, although she was not yet four: "My mummy is pink and my daddy is dark brown. I am light brown but I want to be pink because that is better."
The school I visited had plenty of puzzles, books, and pictures showing black and Asian families. But there was nothing at all that reflected the home lives of bi-racial children. Indeed images and references to this type of family are generally rare. This invisibility in social spaces has added to the feelings experienced by many mixed-race children that there is something wrong with them. Recently Danielle Brown, the actress in Emmerdale and the Spice Girl Mel G's sister, revealed how much "hassle'' it was having a black dad and a white mum, and how she had overcome her feelings of shame and guilt.
Historically these children have always been regarded as a problem for society. In 1930, one social anthropologist wrote: "The problem of the half-caste child is a serious one. The coloured families have a low standard of life, morally and economically. It is practically impossible for half- caste children to be absorbed into our industrial lives."
Britain today has one of the highest rates of mixed-race relationships anywhere in the Western world and the next census is likely to show that the rates are going up. We already know that 40 per cent of black children have one white parent.
Attitudes are changing. There are now more books on the market and a number of self-help organisations that offer support and try to influence policy-makers. But there is still a will not to view the growing community of mixed-race Britons as a distinct group. With racism being so pervasive, it has been easier to talk about divisions between groups than about the way they are subverted by people who fall in love whatever the obstacles.
Social ostracism, apartheid and even lynching have not been able to stop sexual attraction across races. This then becomes a challenge to both racists and those anti-racists who can only read the world in terms of black and white.
What is needed is for the nation to acknowledge the extraordinary history of mixed-race people and the contributions of our many talented and famous mixed-race individuals. Without this, as the academics Barbara Tizzard and Anne Phoenix point out in their book Black, White or Mixed Race?, "mixed-race people have no past, and no heroes or heroines with whom to identify."
A book published today, Remember Me, by Asher and Martin Hoyles, a mixed- race couple, aims to start that process of acknowledgement. There is a vast body of information that even the well-read are unaware of. The writers Robert Browning, Alexandre Dumas and Alexander Pushkin, and the composer Samuel Coleridge-Taylor, were all of mixed race. Bob Marley, Jimi Hendrix, the black American leaders Malcolm X, Booker T Washington and WEB Du Bois, and Arthur Wharton, the world's first professional football player, were all mixed-race individuals.
Come to the present, and the list gets longer. It includes Cleo Laine, Shirley Bassey, Sade, the MPs Oona King and Paul Boateng, the writer Hanif Kureishi, and prominent anti-racists such as Lee Jasper and Linda Bellos. Ms Bellos, Mr Jasper and others define themselves as black, but as the numbers grow and a new generation becomes more vocal it is becoming clear that many mixed-race people feel that this label is an affront to their distinct and complex heritage.
This brings me to a letter I have just received from a young mixed-race girl who is living with a foster-family. She writes: "I am Sandy. I have frizzy red hair and brown skin because my mum is Irish and my dad is black. But I have to explain why I look like this. Even strangers feel they can ask me why my hair is frizzy. These people killed my parents' marriage but they will not destroy me. I am black and white and I am proud. I am the future."