Enchanted gear on mobs or players glow white when they're in fog.

Steps to Reproduce:
1. Make a new Creative world.
2. Spawn a few Zombie Pigmen.
3. Set your render distance to short or tiny.
4. Enchant swords and armor with any enchantments and give them to the Zombie Pigmen.
5. Fly backwards and view the armored Pigmen in the fog.
6. Their armor and sword should glow white.