An Etymological Dictionary of the German Language/Annotated/grau

by Friedrich Kluge

grau, adjective, ‘grey,’ from the equivalent Middle High German grâ (genitive grâwes), Old High German grâo (genitive grâwes); corresponding to Dutch graauw, Anglo-Saxon grœ̂g, English grey, gray, Old Icelandic grár, ‘grey.’ Its origin and further relations cannot be traced; Aryan ghrêw?.