Silvery means shining with a pale grey light. A silvery moon, silvery hair, a silvery sheen.
It describes the quality of the shine rather than the metal, so silvery hair is not grey but lit. It is also used of sound: a silvery laugh is light and ringing, and that sense is old and slightly literary.
1adjectivesilveryShining with a pale grey light.
“The lake looked silvery in the moonlight.”
silvery is a quality.
Silver plus -y. Silver is Old English seolfor, from a Germanic root of unknown further origin.
Middle English
silvery
English, today
silvery
From Middle English silvery, sylvyry; equivalent to silver + y.
Etymology from Wiktionary, CC BY-SA