Rep. Eli Crane, R-Ariz. referred to Black people as "colored people" Thursday in floor debate over his proposed amendment to an annual defense policy bill, prompting a stern rebuke from the former chair of the Congressional Black Caucus. Lawmakers were debating a series of GOP-backed amendments to the National Defense Authorization Act, which the House aims to pass by the end of the week.
I’m no expert, but I suspect that it’s because “colored people” was a term used by racist groups in the past, especially during segregation in America. Just look for old pictures of signs from that era and you’ll see stuff like “Colored Water Fountain”
As for why “people of color” is acceptable, idk. I guess it’s a broader term that applies to more than just black people, but worded differently to show it’s not a segregation era term.