Silver dapples are common in miniature horses. Silvers are also common in Rocky Mountain Horses and Shetland Ponies. Silver is a dominant gene and is noted as "Z" gene. It makes very pretty color.
In the last few years silver genes have found to be in some Quarter Horses, Morgans, Welsh and Gypsy Horses.
I have several silver dapples and a couple of silver buckskin minis. One of the prettiest minis I've seen was a silver bay. It was bay with a silver mane and tail. Really stunning.
The silver gene affects the black coat or black points in horses.