I'm old enough to remember when the acceptable term was "coloured", but I clearly remember that changing in the 1980s as a person I knew got corrected for referring to someone that way at work - so it's not a recent change.
Terminology changes should be determined by the communities that are affected by the terminology. I'm not sure if a consensus could be reached as black people in America or the UK may feel differently from black people in other countries, particularly those where black people are in the majority. Cultural norms are geographical, of course.
Back in the 1960s my (white) gran used to refer to black men as "coloured gentlemen" - never just men. Even she (born at the turn of the century) was trying not to offend in her choice of words, although it sounds daft nowadays. It's not hard to respect other people's preferred nomenclature.