The current color of silver badge looks more like light grey and doesn't have the desired shine. I believe it should be more lightening/flashy silver color. We all know silver badge has more value than bronze but in appearance somehow that differentiation doesn't feel obvious at once. It should actually look like that it has more value than bronze from its look and feel as well.
Have a look at the olympic medals:
Have a look at the color of badges on SO where gold and bronze look very apt. Gold is quite bright (suggesting Rank 1) and bronze is fairly dull (suggesting Rank 3).
This might look like a cosmetic change but of course this certainly gives a sense of achievement so I feel silver badge should be relatively more brighter/shining.