Reference: Colours
Hastings
The colours named in OT and NT, as in other ancient literatures, are few in number, and of these several are used with considerable latitude.
1. White as the colour of snow in Isa 1:18, of the teeth described as milk-white (Ge 49:12), and of horses (Zec 1:8; 6:3,6); also of wool (Re 1:14)
See Verses Found in Dictionary
He replied,
Then he gave orders that they were to make all the people lie down in parties on the green grass;
and his clothes glistened white, vivid white, such as no fuller on earth could bleach them.
then they dressed him in purple, put on his head a crown of thorns which they had plaited,
And the soldiers twisted some thorns into a crown and put it on his head, and arrayed him in a purple robe,
you make it obvious that you are a letter of Christ which I have been employed to inscribe, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of the human heart.
his head and hair were white as wool, white as snow; his eyes flashed like fire,
And when he opened the third seal, I heard the third living Creature calling, "Come." So I looked and there was a black horse; its rider held a pair of scales in his hand,