Specifically relating to Toxic Cables, Silver does not mean brighter.
Frank's small % of gold tames to brightness and sibilance that silver cables get knocked for. Compared to the stock cables, there is a more solid and controlled bass response. Mid's and high's are sharper. With the HD800's this is a good thing since the soundstage is so spacious. A bit more focus can be a good thing.
Did u had the chance to compare a bw with a he500 compared to the sw?