“blá-maðr, m. A BLACK MAN, NEGRO, i.e. AN ETHIOPIAN, Al. 51, Orkn. 364 (referring to A.D. 1152), distinguished from the Saracens and Arabians; three ‘blámenn’ were sent as a present to the German emperor Frederic the Second, Fms. x. 3: in romances blámenn are mentioned as A KIND OF ‘BERSERKERS,’” q.v., Finnb. ch. 16, Kjalnes. S. ch. 15; cp. Scott’s Ivanhoe, note B. See AN ICELANDIC-ENGLISH DICTIONARY by Richard Cleasby and Gudbrand Vigfusson(1874)
The English name “Normans” comes from the French words Normans/Normanz, plural of Normant,[5] modern French normand, which is itself borrowed from Old Low Franconian Nortmann “Northman”[6] or directly from Old Norse Norðmaðr, Latinized as Nortmannus (recorded in Medieval Latin, 9th century) to mean “Norseman, Viking”.[7]
5 Hoad, TF (1993), English Etymology (paperback), Oxford University Press, p. 315.
6 Dauzat, Albert; Dubois, Jean; Mitterand, Henri (1971), Larousse étymologique [Etymological Larousse] (in French), Larousse, p. 497.
7 “Etymologie de Normand” (in French). Centre National de Ressources Textuelles et Lexicales.
While I have seen a possible Viking Connection, this post is highly non conclusive. Far more is needed to help make a Moor and Norman Connection, that is relative to “Blacks”. Perhaps there is, however, a White Moor connection. Norsemen were, indeed, profound Usurpers.