I was just reading a book about Postcololniality in Belgium (related to the Congo) today, in which it is said that "People of color" was indeed a word that replaced "nigg*rs" and "indigenous". A euphamized PC way of calling the same people.
All in all, its very existence emphasized the fact that the "standard" is White, and that all other people have to be qualified since they diverge from the standard. (In Europe it's also a convenient way of not calling Whites "White", since you're not talking about "Blacks" neither. It keeps the discussion vague).