This is a hard question, as a wrong usage can cause offence. I suppose the white western culture (Europe, US, Australia's also included) still has cultural guilt over the slavery and maltreatment of 'coloured' people in the past.
I think Adhi has the best suggestion: refer to the person's ethnic group instead of the skin colour. If you're not sure, then 'black man' might do.
I recently discovered 'negro(id)' as a race classification has now been split into 2 groups! Capoid and Congoid (south and central Africa).