This is just what I have picked up on this forum (we don't have silvers in my country) but silver x silver produces a fatal gene which means a lot of the eggs won't develop. Some will though and all will be silver. People tend to cross them with the pharaoh colour as that is the underlying pattern of the silvers (I think - someone can correct me if I'm wrong). This will give you a 50/50 split for silver and pharaoh coloured offspring. If you cross with the Tibetan colour you will get the odd 'charcoal' coloured offspring. I'm pretty sure you can have silver tuxedos which would be the result of crossing them with white birds. Good luck with your breeding.