rosy (adj.)youdaoicibaDictYouDict[rosy 词源字典]
late 14c., of a color, from rose (n.1) + -y (2), probably modeled on Old French rose. From 1590s of healthy complexions; 1775 in the sense "cheerful;" meaning "promising" is from 1887. Similar formation in Middle Dutch rosich, Dutch rozig, German rosig.[rosy etymology, rosy origin, 英语词源]