An Etymological Dictionary of the German Language/schwarz
schwarz, adj., ‘black, swarthy, gloomy,’ from MidHG. and OHG. swarz, ‘dark-coloured, black’; a common Teut. term, most of the words denoting colour, except the recent loan-words, being part of the primit. Teut. vocabulary (comp. gelb, rot, braun, &c.); Goth. swarts, OIc. svartr, AS. sweart, E. swart, Du. zwart, OSax. swart. OIc. sorta, ‘black colour,’ sorte, ‘black cloud,’ and Surtr are in a different stage of gradation. The common Teut. shwarta- is usually connected with Lat. sordes (for *svordes?), ‘dirt,’ and suâsum (for *suarsum), ‘black colour, dirty spot’; Lat. surdus ‘deaf,’ has also been referred, but with less probability, to the root sword, surd, ‘dark.’