Were the Sumerians black?

They referred to themselves as sag.giga (trans. 'the black-headed peoples'). Berossus the Babylonian historian called them 'black-faced foreigners'. They spoke an agglutinative language phylogenetically separate from the Semitic tongues around them. Were these pioneers of writing, agriculture, and forefathers of the long-lived traditions of Mesopotamian mythology - of which Judeo-Christianity is a distant descendant - recent immigrants out of Africa?