Language is and always will be an essential element in the struggle for understanding among peoples. Changes in the words and phrases we use to describe each other reflect whatever progress we make on the path toward a world where everyone feels respected and included.
A Google Ngram search comparing the frequency of the use of "colored people," "minorities" and "people of color" delivers interesting results. The use of the phrase "colored people" peaked in books published in 1970. For "minorities," the top-ranked year was 1997. Since then, the term has steadily declined but continues to significantly outstrip the use of "people of color," which reached its apex in 2003 (although it is important to note that 2008 is the latest year for which results are available).
Let's consider the evolution of that ubiquitous phrase, "people of color." It's not new.
A little research into early sources turns up "An Act to Prohibit the Importation of Slaves into any Port or Place Within the Jurisdiction of the United States" (signed in 1807), which applied to "any negro, mulatto, or person of colour" indicating that the term was well-enough established to be used in the text of legislation.
People who fit this broad category could no longer legally be brought into the country for the purpose of involuntary servitude. But the precise definition of "person of color" has varied among the states and over time.
As the Baltimore Afro-American newspaper noted in November 1912:
"The statutes of Kentucky, Maryland, Mississippi, North Carolina, Tennessee and Texas assert that 'a person of color' is one who is descended from a Negro to the third generation, inclusive, though one ancestor in each generation may have been white. According to the law of Alabama one is 'a person of color' who has had any Negro blood in his ancestry for five generations. ... In Arkansas 'persons of color' include all who have a visible and distinct admixture of African blood. ... Thus it would seem that a Negro in one state is not always a Negro in another."
The Oxford English Dictionary's earliest reference for "person of color" is from the French gens (or hommes) de couleur, in the late 18th century. A 1797 survey of the population of what is now Haiti described three classes of people, including "The class which, by a strange abuse of language, is called people of colour, originates from an intermixture of the whites and the blacks."
"Person" or "people" as a term for human beings, that's pretty much uncontroversial. But color which can be used as a noun, an adjective or a verb (transitive and intransitive) is a word packed with history, prejudice and confusion when it's used to describe someone's complexion as an indication of race or ethnicity.
The adjective form "colored" we hardly need the OED to confirm, but it says the term is now:
"Usually considered offensive ... Coloured was adopted in the United States by emancipated slaves as a term of racial pride after the end of the American Civil War. It was rapidly replaced from the late 1960s as a self-designation by black and later by African-American, although it is retained in the name of the National Association for the Advancement of Colored People. In Britain it was the accepted term for black, Asian, or mixed-race people until the 1960s."
In a 1988 New York Times column about the phrase, the late great language maven William Safire pointed out that Martin Luther King Jr. referred to "citizens of color" in his speech at the 1963 March on Washington. Safire also quoted an NAACP spokesman:
" 'Times change and terms change. Racial designations go through phases; at one time Negro was accepted, at an earlier time colored and so on. This organization has been in existence for 80 years and the initials NAACP are part of the American vocabulary, firmly embedded in the national consciousness, and we feel it would not be to our benefit to change our name.' "
Safire continued in that 1988 essay:
"Colored people (which in South Africa means 'people of racially mixed ancestry') has in the United States a connotation different from people of color. ... Colored is often taken as a slur, even when not so intended, and so this term first used with this meaning in 1611 by the historian John Speed as 'coloured countenances' is better replaced by its synonym as noun and adjective, black. People of color, on the other hand, is a phrase encompassing all nonwhites. ... When used by whites, people of color usually carries a friendly and respectful connotation, but should not be used as a synonym for black; it refers to all racial groups that are not white."
When I was a kid, the "flesh" crayon in a box of Crayolas was pink, even though no one actually has pink skin (except maybe after a day on the beach without sunscreen, when I could go all the way to orange-red). The company renamed it "peach" in 1962, and now promotes a "Multicultural" box of crayons in eight "skin hues" Apricot, Black, Burnt Sienna, Mahogany, Peach, Sepia, Tan, White.
The first thing I learned in color theory as an art student was that, when you're talking about light, white means all colors and black is the absence of color, but if you're referring to paint, then white is no color and black contains all colors.
Contemporary artist Carrie Mae Weems produced a series of photographic portraits of African-American children and called it Colored People. A New York Times review of an exhibit of her work described how she "tinted the prints with monochromatic dyes: yellow, blue, magenta. The results were beautiful ... but the colors carried complex messages. They are reminders that the range of skin colors covered by 'black' is vast."
"Person of color" is a useful term, because defining someone by a negative nonwhite or other than white seems silly. But some white folks object to the phrase, too, because, hey, we do have color.
One definition of white, from the Random House Unabridged Dictionary, is "marked by slight pigmentation of the skin." And the term seems to be replacing "minorities," which makes sense, since minorities can be a demographic inaccuracy. In U.S. history, "person of color" has often been used to refer only to people of African heritage. Today, it usually covers all/any peoples of African, Latino/Hispanic, Native American, Asian or Pacific Island descent, and its intent is to be inclusive.
I think professor Salvador Vidal-Ortiz summed it up well in the Encyclopedia of Race, Ethnicity and Society:
"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."