You’re exactly right. There *is* only one “race,” with multiple ethnicities, cultures, and so on.
I’ve said it for decades, skin color is just a paint job. Look at the Wayans brothers in “White Girls”. Or Ted Dansen, or Governor Northam, or anyone who did “blackface”.
If I packed up and moved from Houston Texas to Alaska, I’d wager I’d become a lot lighter skinned. If I packed up and moved to an even more tropical/desert climate, I’d end up darker skinned.
But, I’d still be the “white” boy with sickle cell.