He remembers one of his friends saying: "We hate niggers - not you Len, because you're one of us, but we hate niggers."
Henry believes that young people would be less likely to make hurtful racial comments like this or be prejudiced if they had access to information dispelling racial stereotypes and explaining cultural differences.
As a trustee of Comic Relief, he suggested that the charity do something to stimulate cultural exchange and show that it is not something to be afraid of.
The result is Britkid, a ground-breaking interactive website that aims to help young people deal with racism and explore their attitudes to living in a multicultural society.
The site was sritten by anti-racism researcher, Chris Gaine. It is funded by Comic Relief, the Chichester Institute of Higher Education and the European Commission, the Runnymede Trust and ChildLine.
It is aimed at 11 to 15-year-olds who do not live in areas of ethnic diversity, as well as teachers and youth group leaders.
Britkid features a number of characters from different ethnic backgrounds,who all live in the fictional town of Britchester. Users become the "new kid on the block" and find out how the others deal with issues of identity and race.
A teachers' guide provides quick access to specific information and on using the site with a class.
Henry thinks that the wealth of information and statistics available on the site will give young people the power to challenge stereotypes.
Dr Gaine said Britkid would help to alleviate the lack of anti-racism teaching materials. He hoped it would help teachers to discuss racism issues with students. Many believed it was an important issue, but were unsure about how to raise them in class, Dr Gaine said.
Kevin Cahill, chief executive of Comic Relief, expected Britkid to be the start of a longer-term commitment by the charity to combating racism in Britain.
Britkid is at www.britkid.org