I don't have any at the moment, but I sure want one! Here's an example of dark silver: I like this color because it signifies original skin, a great factor in me buying 19th C coins. Nothing looks sillier than a blast white coin made 160 years ago.
So I picked up this 1878-S Long Nock Morgan on Ebay once. This was the obverse: Some previous owner was, however, nice enough to thoroughly clean the reverse to ensure the Long Nock was visible: All the same, the feature wasn't mentioned in the auction, I picked it up for a song and doubled my money on the flip.