Danes have the same problem trying to figure out the roots of the term 'black Danes'. My grandfather was a black Dane with dark brown hair, a dark complexion and blue eyes. Where did it come from?

Apparently the genetic mixing occurred way back in the days when there were tribes battling in Northern Europe. The Arles were the dark ones and conquered the plains all the way to the coast. Could it be when the Black Danes found Ireland, they produced Black Irish offspring?

Who knows? My guess is that the terms come from appearance only. Genetic mixing has been occurring for centuries.