"the color yellow or one of its hues," Middle English yelwe, from the adjective and from Old English geolo, geolu, "yellow" (n.), from Proto-Germanic *gelwaz (source also of Old Saxon, Old High German gelo, Middle Dutch ghele, Dutch geel, Middle High German gel, German gelb, Old Norse gulr, Swedish gul "yellow"), from PIE root *ghel- (2) "to shine," with derivatives denoting "green" and "yellow" (such as Greek khlōros "greenish-yellow," Latin helvus "yellowish, bay"). Occasionally in Middle English it was used of a color closer to blue-gray or gray, of frogs or hazel eyes, and as a translation of Latin caeruleus or glauco.
-y 2
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.