How come the term ‘person of colour’ ain’t as offensive as ‘coloured person’?

Both terms literally refer to a person. Both terms have ‘colour’ in them. I haven’t heard ‘coloured person/people’ (though have read in a book with a racist person in it) but have heard many times ‘poc’ or ‘person/people of colour.’ I find both terms offensive and racist. I am bloody disgusted by those terms.

How come the term ‘person of colour’ ain’t as offensive as ‘coloured person’?
Post Opinion