It’s also quite rare to find someone with black hair and blue eyes outside of Ireland or Irish ancestry. That is the ‘typical’ black Irish, at least according to my grandma—who herself had the red hair of the Nordic invaders, but she married a black Irish. My dad had black, curly hair and gray-blue eyes. I got his hair, but my maternal Spanish grandad’s hazel eyes.
You’re probably right; that’s the way I understand it at least. Most I know like that are indeed of Irish or Scottish background. It’s a striking combination. Strikingly beautiful, I’ve often found.
My mother’s Irish family was interesting ... four sisters, two “black Irish” and two Nordic blondes. All very, very fair skin and incredibly blue eyes. (also, 2 were tall/2 short .. go figure). Genes are a funny thing.