Usually the plain English descriptive ‘brown-complexioned’ — though the Galway Brownes arrived as Anglo-Normans and became one of the fourteen ‘Tribes’.
Mixed Origin · Root meaning ‘brown’
Brown is most often a straightforward English or Scots descriptive surname, ‘brown-haired’ or ‘brown-complexioned’. But the Brownes of Galway are a separate and better-documented story: an Anglo-Norman merchant family who became one of the city's fourteen ‘Tribes’, later rising to the Earldom of Altamont and the Marquessate of Sligo.
One root plain and physical, the other landed and titled — both, honestly, are Brownes today.
Irish form: de Brún