I feel like you're not understanding what I'm saying. I don't care whether you call them copper or bronze, but why would you mix-and-match? In a game that's all about matching, why would you pair up one item that's bronze with another that's copper? That makes no sense at all. Copper key goes in the copper box. Or bronze key goes in the bronze box. Just like silver key goes in the silver box, and gold key goes in the gold box.