I agree, i only heard this term from some Americians while in the US traveling and had to look it up. It's simply implausible to attribute supposed Mediterranean features to a few stragglers shipwrecked in scattered areas 400 years ago, there is certainly no history or remembering of Spanish blood in there areas. If one was to say that dark hair and/or dark eyes are the result of Spanish blood then they must have been throughout the island ag streachailt leathair.

I'm think i'm only repeating what Ard Mhacha & Learaí na Láibe were saying but this seems to be just descendent of emigrants now living in America romanticing their past and retaining fragments of it, which now form incorrect perceptions. Colours when used in Ireland tended to be emotional description (An Fear Rua/red man = Angry man, An Fear Dubh/dark man = the Devil), not expressing physical attributes. There is no usuage of the term Black Irish in relation to Armada survivors in Ireland, and no record of it here, including in the irish-speaking areas, the places that have retained most of our folklore. If Irish-americans want to use it fine, but its history they've invented.