Hey you stole my idea . It's a good idea though. I was hoping they'd go a step further and make different resources in game make different colored armors and weapons.
Iron-Steel = Grey weapons and armor
Mithril = kinda blueish weapons and armor
Bloodstone = Red weapons and armor
That would bring a lot to the table for unit design and is relatively easy to do. Just recolor the standard model/skins for the items in game.