An Etymological Dictionary of the German Language/Annotated/schwarz
schwarz, adjective, ‘black, swarthy, gloomy,’ from Middle High German and Old High German swarz, ‘dark-coloured, black’; a common Teutonic term, most of the words denoting colour, except the recent loan-words, being part of the primitively Teutonic vocabulary (compare gelb, rot, braun, &c.); Gothic swarts, Old Icelandic svartr, Anglo-Saxon sweart, English swart, Dutch zwart, Old Saxon swart. Old Icelandic sorta, ‘black colour,’ sorte, ‘black cloud,’ and Surtr are in a different stage of gradation. The common Teutonic shwarta- is usually connected with Latin sordes (for *svordes?), ‘dirt,’ and suâsum (for *suarsum), ‘black colour, dirty spot’; Latin surdus ‘deaf,’ has also been referred, but with less probability, to the root sword, surd, ‘dark.’