No one would have been listed as "Black" in 1961. Colored or Negro (or Negroid) were the terms in use back then. My mother still uses "colored", and she doesn't live in the South either. However since BHO Sr. really was Black, by comparison to most Americans with African ancestry, I guess they might have used "Black African" or "African Negro" or some such. Hawaii was a lot different than the rest of the country, since they'd been mixing things up since before they became a US territory
They were briefly the Sandwich Isles under the Brits, which is why their state flag looks like this:
The eight stripes are for the eight main islands. The field is obvious.
The U.S. Census didn’t have arabs use black though. Arabs were using white/caucasion, Turkish or Ottoman.