black/irish (an amazingly common mix in the UK for some reason

Not that amazing really, there's a lot in common. The only "ethnic insult" I've ever quite liked the sound of is "toasted Irishman", meaning someone from the West Indies. (I put the quotes on "ethnic insult" because I don't think that's an insult, though it was often meant to be.)

And it's fitting that one of the most popular saints in Ireland is St Martin Porres, who was a black slave in Peru.