Explanation: Very simply "people of color" means non-white. I don't think this would be politically uncorrect in Spanish. For some reason, the term "non-white" stimulates the hypersensitive PC-meter, as though there were something wrong with not being white.
I'm going with "gente no blanca" - my logic is on my terminology blog: SpanishForSocialChange.com
many thanks to all for the discussion! 4 KudoZ points were awarded for this answer
Why don't you give little more context? In Spanish, the result will not depend on political opinions or euphemism, but on the kind of text and context implied. Some translations below are good in formal context, others in informal...
Furthermore, in the absence of any guidance to the contrary, you can go literal with no fear of criticism. Any other solution involves risks you might not wish to take. After all, you are not saying it, you are just translating it.
I think you can get the idea that this can be rather controversial, so what I would recommend is to discuss it with your client and let the client make the decision. That lets you off the hook.
Absolutely, we do all have a color. I think when we answerered thinking about "black people" was with no bad intention, for sure. Pero seguro, depende del contexto, como dijo "emege". By the way, I'm "latina", and I'm so proud of this!! ;)
We do guess that "people of color" are black people? [From black Africa, that is]. Not "asian", not "latinos", not "arabic" whatever. We do all have a color.
Dependerá de para qué país sea el texto. Por ejemplo, en España actualmente su usa el políticamente correctísimo eufemismo "(africanos) subsaharianos" para referirse a la gente de raza negra. Pero para América no te servirá... :-)
If you're looking for something "politically correct" then you are not being faithful in the translation, unless the client has specifically requested editing. "Minorías étnicas" is not the same at all.
The translation workplace 
Translation industry wiki
peer agreement (net): -1
