Learnt my lesson in the early 80's. Went for an interview at a college wanting to study to be a Youth worker. Used the word 'coloured' when I wanted to refer to black/asian people. Interviewer very politely, and in a non threatening way, told me why many black, asian, people consider the term so offensive. When used by white people the term can refer to anyone who they don't percieve as white. Of course being white, my skin is just as much "coloured" as anyone elses, so it really is a meaningless term. It is like saying us (whites) and them (coloureds, all the others) as if white is the norm. Not very accurate and likely to cause offense; and this is usually the last thing people desire. I think many people use coloured because they think it less likely to cause offense, "black" sounds harsh, and brings with it lots of negative connotations.
And just to make things more difficult, I've never seen anyone who is really black, anymore than I have ever seen anyone who is white, and there are many people who find the term "black" when applied to them offensive, hence people use African American, Asian, etc refering to peoples origin.
Not easy is it? Particularly when you are a pale skinned bleeder, desperate not to offend, and trying to appear all PC.
The answer of course would be to call everyone by the term they themselves were comfortable with (impossible), or, as I do, avoid refering to anyones ethnicity at all unless I absolutely have to, it's a feckin minefield. It can't be beyond the wit of people to think of other ways of describing folks other than the colour of their skin or their origins.
Coloured
When I was born, I was black.
When I grew up, I was black.
When I get hot, I am black.
When I get cold, I am black.
When I am sick, I am black.
When I die, I am black.
When you were born, You were pink.
When you grew up, You were white.
When you get hot, You go red.
When you get cold, You go blue.
When you are sick, You go purple.
When you die, You go green.
AND YET YOU HAVE THE CHEEK TO CALL ME COLOURED!!!