I'm surprised, growing up in that era, I don't remember it that way, it seems that black didn't come in until 5 years later or so, maybe even "colored" was more current at the time>
I’m not sure of the exact years. “Colored” was the earlier polite term, and “black” was avoided, but the black activists attacked “colored” as demeaning and insisted that they were black. “Negro” had been the neutral, scientific term, but black replaced it. whether that was beginning to happen when Obama was born, or a little later, I’m not sure.
“Persons of color” later came in as a correct term, but “colored” is still out. And of course “persons of color” means to include all the designated minority groups except whites. But I don’t believe Japanese or Chinese or American Indians would be inclined to use it to describe themselves except in academic settings. In other words, it supposedly means all people except whites, but in practical usage usually means blacks.