I allways had good luck in the SW rivers with cerise and black marabou combination. I usually tied it on a downturned eye hook (like a tiemco 700) and wrapped the shank with silver braided tinsel or pearl tinsel. The addition of holographic flash material or flashabou in pearl, pink, or silver helped depending on the flow and colr of water. Keeping it slim in profile seemed to be more effective than building a bushy fly for whatever reason. But for silver in the rivers cerise and black was my go-to color combo.