Peter Rhodes on a torrent of filth, a star's dilemma - and what colour is a lawn?

Couldn't happen here, could it? Or so we thought until the BBC's newsreader Sean Ley told us, in the wake of the David Amess killing, about a suspect “who has Saturday been named as...” He went on to explain that the suspect “was arrested at the scene Friday.”

A rare screening of that fine film Mona Lisa (Talking Pictures) reminds us that it is – or rather, was – perfectly possible to make a movie about the most depraved aspects of human behaviour, from prostitution to paedophilia, without bombarding viewers with effing and blinding. The torrent of f- and c-words we get today, even in otherwise-excellent TV comedies (This Country, Back to Life, et cetera) is offensive, unnecessary and for many viewers, literally a turn-off.

For me, Mona Lisa was a reminder of interviewing the film's star, Cathy Tyson. She was appearing as Portia in The Merchant of Venice at Birmingham Rep, and having a crisis over the lines. Shakespeare's text has Portia spurning the black Prince of Morocco and “all of his complexion.” Tyson was agonising over whether, as a black woman, she could deliver such lines. As I tried to interview her, she was stressed, upset and uncommunicative. After discussing the issue with the director, some lines were cut and she went on to get rave reviews. In case you thought this sort of racial issue was only a recent thing, Cathy Tyson's dilemma happened almost a quarter-century ago, in 1997.

Thanks for your emails on the subject of living with colour blindness. One colour-blind reader reported a common question asked by the curious: “What colour do you see grass?” The answer, of course, is green (because everybody knows grass is green). However, if the green turned overnight to brown, red, orange or grey, the colour-blind person might not notice. I have always considered my own colour-blindness as nothing more than an inability to name some colours.

The reader I most sympathised with wrote: “After over 40 years of marriage my wife still says 'Oh look, isn't that beautiful?'" as we pass a field of muddy, wishy-washy brown pretending to be a poppy field.”