Silver is surprisingly difficult to get a middle name where it doesn't end up sounding like you are describing the middle name or naming a variant of it (like a type of plant, melon, bird etc)
It's a very pretty name though. And I don't think the middle matters too much. You wouldn't say them together that much.
Silver Elise
Silver Elaine
Silver Joy
Boys (these are apparently popular Victorian names):
Arnold, Augustus, Baxter, Bram, Cassius, Clarence, Edgar, Edwin, Elmer, Everett, Floyd, Franklin, Grover, Hugh, Ives, Joules, Larkin, Luther, Otto, Phineas, Silas, Tesla, Wellington