Are Denzel Washington and Will Smith the first African-American stars on the A-list to regularly secure roles that could have been offered to their white contemporaries?

For all the success of Sidney Poitier, that fine actor was, almost invariably, cast in parts where his race was part of the story. By way of contrast, Washington can, it seems, compete with Brad Pitt and Russell Crowe to play the latest grizzled cop or conflicted lawyer.

"Here's the thing: it's a business," Washington says. "And when you make money they don't care what colour you are. We are still struggling the most with the executive positions. There has never been an African-American head of a studio. And if there were, there would be so much pressure on him, he might be frightened to start making all these black films. As things are, white executives are going to want to tell their own stories. That's understandable."

There is still some way to go with actors as well. Too few female African-American stars have, Washington admits, made it into the big time.

"At the same time, I look at the pioneers of my generation - directors like Spike Lee or John Singleton - and I think the door is getting pushed further and further open. It's happening one inch at a time. A lot more people are getting work and, like I said, if the industry sees there's money in it they get interested. The only colour they're really interested in is green."