Okay that article says nothing about the term "colored people" being assigned to them. Nor does it say anything about what the difference is. And how does "People of Color" connotate a community while "colored people" doesn't? You can describe baseball fans as "baseball fans" or "fans of baseball" and it still has the same meaning.
last quote of the article:
"Colored people" was used to degrade and ostracize PoC by white people. There is something to be said about putting the noun before the adjective because it brings the definition back to being about the person, not their attribute (ex. person with Autism rather than autistic person is another one I've seen argued). It's about self-designation and reclaiming personhood. eta: this wound up in my drafts for a long time and goo hit the point pretty well"People of color explicitly suggests a social relationship among racial and ethnic minority groups. ... [It is] is a term most often used outside of traditional academic circles, often infused by activist frameworks, but it is slowly replacing terms such as racial and ethnic minorities. ... In the United States in particular, there is a trajectory to the term — from more derogatory terms such as negroes, to colored, to people of color. ... People of color is, however it is viewed, a political term, but it is also a term that allows for a more complex set of identity for the individual — a relational one that is in constant flux."
Salvador Vidal-Ortiz, Encyclopedia of Race, Ethnicity and Society
The way I've been taught is how the words define you. There is a similar discussion about whether to say "disabled people" or "people with a disability." The idea is, "people of colour" indicates you are a person first, and being coloured is a secondary feature. "Coloured people" indicates you are first defined as coloured, and as a person after the fact.