The silver dragon is a treasure dragon, and they are a little more difficult to breed than some other dragons. Just keep at it. Some successful methods are:
Iceberg + Steel (reportedly the most successful at about 14%)
Steel + Storm
Cold + Mine
Cold + Metal
ironwood dragon and storm dragon
If you breed any type of dragon as long as they are lv 10 you will get them
You don't breed a Kairos Dragon in DragonVale. You have to get parts to complete it.
U breed the two dragons ice and sandstorm
you breed a ice dragon with a mine dragon
You have to breed a plant and a fire dragon.
As of July 2012, there has not been a star dragon in DragonVale.
You have to breed a metal and a water dragon together.
You have to breed a sun and moon dragon together
You have to breed a plasma dragon with a salamander dragon.
Breed mine( cold and metal) with cold and you may get it Add me on game centre : blue zebra world
Breed the earth dragon with the fire dragon.