Fifty years after many parts of Britain became multicultural, television still does not know how to cope with the issue of race.

More often than not, ­British TV behaves like a benign, blimpish white man from the south of England, where the vast majority of television is still made, who has just stumbled into a multicultural centre and is desperately trying to do and say the right thing and often ends up doing and saying the wrong one.

You can see this in the recent decision to introduce a black character to Downton Abbey. Julian Fellowes, the show's creator, says the world has been unjust to black people. "If I was growing up now," he said recently, "I would want to see some winners among that group."

His response has been to cast Gary Carr, who has just started as the jazz musician Jack Ross. He is the first black character in the series, but the fact he is there shows how far television has come on race, but also how far it still has to go to move beyond casting that looks tokenistic and slightly patronising.

I saw this for myself at the weekend when, as well as Downton, I watched an old 1974 ITV production of The Merchant of Venice on DVD. The production, starring Laurence Olivier and directed by Jonathan Miller, is good apart from the extraordinary sight of a white actor blacked up as the Prince of Morocco. This was not so unusual in the 70s - Olivier would later black up for a film version of Othello - but it was partly because there were few actors of ethnic origin working 40 years ago. Those who were around - such as Burt Kwouk or Renu Setna - you tended to see over and over again.

As more black actors began to come out of drama school, white actors blacking up became unnecessary but it is still taking a long time to change the all-white look of television. I was speaking to the TV writer and playwright Rona Munro this week and she reminded me that the episode of Doctor Who she wrote was the first to feature a black character who was not an alien. A breakthrough, but a long time ago - 1989 - and one of only a few in the way television tackles race.

Another, two years after Munro's episode of Doctor Who, was The Real McCoy, whose star Felix Dexter has just died. Dexter was part of a team of Afro-Caribbean and Asian performers who wrote and performed sketches. Also part of the team was Meera Syal, who later appeared in Goodness Gracious Me and The Kumars at No42.

What is remarkable about those shows is that they are still unusual and that fact cannot be hidden by glitzy, politically correct casting in Downton or automatic multicultural casting in television adverts for soap powder or insurance. The change in the way women and gay people were portrayed on television only happened when middle-class, middle-aged men lost their stranglehold on the writing, production and direction of television.

Now the same needs to happen with race. A white man who runs Downton Abbey creating a black character is good news, but it is only when more black men and women are making television that the way they are portrayed on television will change. When the faces behind the camera change, so will those in front of it.