There are more words for gray and pale than white in Greek.
The two main words from which a variety of adjectives and nouns derive are
λευκός pale white and ἀργής shiny white like silver ἀργυρός
White objects were also often compared to
Snow νιφος or stone λυγδος or marble μαρμαρος.
The Greeks seem to have associated the quality of whiteness with shine and gleam and brightness.
Color names begun as names. Color as an abstract concept developed later.
The ancients had to write about color by comparing it to objects.
More examples of this soon.