From an unused root meaning to dazzle; sheen, i.e. Whiteness -- white.
H6713. tsachar
[צַ֫חַר noun [masculine] reddish-gray, tawny; — צָ֑חַר צֶמֶר Ezekiel 27:18 wool of reddish-gray, tawny wool, or (Hi-Sm Krae), of land Sachar (si vera lectio; Co strike out צחר as dittograph).