I too find this current situation utterly frustrating and confusing. Evidently it is wrong to say 'A coloured person', but acceptable to say 'A person of colour'. No doubt someone will correct me, but is this not simply rearranging words?
I'm not correcting you, but responding to your question. It's not just rearranging words. To describe someone as 'a coloured person' suggests that white is the default, and that their colour is the important thing about them. It was also a term used to discriminate against anyone who wasn't white in Apartheid South Africa. Using 'people of colour' puts the emphasis on the person, if you see what I mean, and doesn't have the Apartheid connotations.
I understand that it's confusing, as 'acceptable' terms change all the time, but as I understand it the logic is as I describe above.
Re Torode - I have no idea if this is true, but I have read two things that he is supposed to have said. One is that he used an Australian term for a sandwich that is acceptable in Australia, but not here. It was in the title of a children's book that was popular in the past, about a boy who was chased by tigers and tricked them into running round a tree until they melted. It was also used by Alf Garnett, and on that Love Thy Neighbour programme. The other thing I read was that he used an offensive word that is a slur against travelling people.
As ever, these things are subjective, but if the first is true then he may well have been unaware that the term is offensive here - the book hasn't been around for years (I think JT is in his 50s), and if he apologised when its offensive nature was pointed out, then fair enough.
If it is the latter, then there is no excuse. I can't see how a word like that can be anything other than offensive (and I'm not sure how it could easily come up in a cookery show, either).