The color difference between gold and bronze badges are too subtle to be noticed. Can they be made more saliently different?
Especially, with black background, they are almost indistinguishable to me. On the page that shows the inventory of badges, where the badges are aligned vertically, I almost cannot tell which ones are gold and which ones are bronze.
I agree with some of the proposals below, but even just making the gold more yellow and bright, and the bronze more brown/orange and dark can help. Or if just either of them were outlined with a different color, that could help too.