'White' in the Bible

I beheld till thrones were set, and the Ancient of days did sit: his raiment was white as snow, and the hair of his head like pure wool; his throne was flames of fire, and its wheels burning fire.

And some of the wise shall fall, to try them, and to purge and to make them white, to the time of the end: for it shall yet be for the time appointed.

Many shall be purified, and be made white, and be refined; but the wicked shall do wickedly: and none of the wicked shall understand; but the wise shall understand.