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 answered them, "When it is evening, you say, 'It will be fair weather; for the sky is red.'
Then he commanded them to make them all sit down in groups on the green grass.
and his clothes became dazzling, exceedingly white, as no launderer on earth could bleach them.
And they clothed him in a purple cloak, and they twisted a crown of thorns and put it on him.
And the soldiers twisted a crown of thorns and put it on his head, and they clothed him in a purple robe.
You show that you are a letter from Christ, delivered by us, written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of carnal hearts.
His head and hair were white like wool, as white as snow, and his eyes were like a flame of fire;
When he opened the third seal, I heard the third living creature say, "Come." And I looked, and behold, a black horse; and its rider had a pair of scales in his hand.