perse (adj.)youdaoicibaDictYouDict[perse 词源字典]
late 14c., "blue, bluish-gray," later "purplish-black," from Old French pers "(dark) blue, livid; wan, pale," from Late Latin persus, perhaps a back-formation from one of the early European forms of Persia.[perse etymology, perse origin, 英语词源]