television Comic Asides (BBC2) Jasper Rees hails the new pretender to the throne of Lenny Henry

Bill Cosby became the US network's most prominent black performer by glossing over the race issue. Lenny Henry gained equivalent status in Britain by shoving it gently down his audience's throat. This looks like a measure of our greater tolerance: colour gags, we can take them on the chin.

But there's a historical reason why Henry finds it easier to laugh about race. British black humour has its roots in the West Indies, whereas its American equivalent has no recent memory of anywhere else. It stands to reason that an immigrant minority has a more separate sense of identity than an indigenous one. This gives it an extra set of jokes to crack, all of them about one race shoehorning itself in the space occupied by another.

This will change, though, because the time will come when jokes about first-generation Jamaicans will be as quaint as Ealing comedies are now. The running gag in Desmond's, currently being repeated on Channel 4, is the cultural gulf between the parents with Caribbean accents and their children, who speak perfect Peckham. The same set of tensions were aired in Felix Dexter on TV (BBC2).

The best sketch from a promising collection cast Dexter as a respectable, integrated solicitor, who swiftly deals with a white client's case in fluent, impenetrable legalese. When a black client is ushered in next, the solicitor drops into black patois, but using received pronunciation. It's funny because it's very silly, but beneath the silliness is a complex agenda, to do with the black man's invasion of the white professions, and the absurdity of brotherhood rituals when taken out of context. Line of the night came from the lawyer advising his client, who turns out to be a doctor, to avoid police harassment by driving a Saab: "Black man, Swedish car: you could be a diplomat, an academic, a friend of Desmond Tutu. They can't tell.''

Other sketches also up-ended stereotypes and gave them a good shake. A running sketch about an assiduous ticket collector who preys on a fare- dodging city gent made the guardian of moral standards black instead of white. Some of Dexter's caricatures are survivors from The Real McCoy, the all-black sketch show, as are one or two actors. The intention is plainly to assemble a pool of characters who, in the manner of Harry Enfield, can bring an established set of characteristics to each new sketch. At the moment the gallery isn't quite full enough.

When Lenny Henry first appeared on our screens he was a talented curiosity. It's a sorry indictment that no black comedian has since challenged his supremacy. Having delivered the most satisfying of this batch of Comic Asides, Dexter deserves his own series in which to try.