The scales of this tall, elegant dragon shine like polished silver, and its tail has a feathered appearance.
Upon reaching adulthood, silver dragons have acquired sufficient experience and knowledge of the world to set up a safe lair. While other dragons are content to remain within their secluded homes, silver dragons often risk leaving to meddle in humanoid affairs.
The life of an adult silver dragon is one of devotion and self-sacrifice, with every one of them relentlessly dedicating themselves to what they deem to be fair and good. It is often a trying path, as the dragon works to preserve, assist, and support from the shadows, expecting neither reward nor recognition. A silver dragon's tremendous determination usually allows them to bear such a life, but some can be engulfed by resentment, bitterness, or resignation, which leads to selfishness, or even corruption. A corrupted silver dragon is as rare as it is dangerous.
5e SRD
Lawful good dragons that dwell in high places and often use shape-changing powers to observe and help people
Dwelling in high places such as mountaintops or among the clouds, like gold dragons, silver dragons epitomize law and goodness. They are interested in the ways of man and often use shape-changing powers to watch, observe and help people. They prefer to have their lairs in places isolated from prying eyes, however, and thus often place their entrances in lakes or ponds. They have found that their treasure hordes are tempting targets for evil or even neutral adventurers.
Silver dragons usually speak (75%), and if they can speak, usually (75%) cast magic. Occasionally (15%), they will be found asleep. If the dragon is asleep, there is a 1 in 6 chance that it will awaken in the presence of adventurers.
Dragons also sometimes feign sleep.
OSRIC