According to her family, Christie loathed the first adaptations of her books into plays (by other people) because they didn’t make radical enough changes. She believed that when work shifts medium, the story should shift. Her family - who licence all her work - have said they believe she would have been happy to see the diversity in this programme.
Also, I can’t believe anyone would want Christie’s work - particularly her early books - dramatised exactly as they were written, littered with anti-semitism, anti-Catholicism, and racism. Indeed, over time Christie appears to have shifted her views, probably as a consequence of seeing the impact of the Nazis, changing the way she wrote about Jews, black and Asian people and other foreigners, and agreeing that her American books should have offensive language removed- it’s to the shame of her British publishers that they did not insist on the same, until recently.
On the issue of language ‘coloured’ is an offensive and inappropriate term when used to describe black and other non-white ethnicities. I’m sure, of course, that anyone using it on Gransnet only does so because they didn’t realise that.