The striped portion is free from any fading or brown tinge and should be dark.
When black and silver miniature schnauzer puppies are born, they are born black and tan, or black copper of some sort. As they proceed to get older, that tan or copper color changes to a silver.
Markings on the muzzle, eyebrows and inside ears, across the chest and down the legs and feet and the under tail are silver. black eyes and black pads and black nose.
When you look at black and silver miniature schnauzer puppy, look at the top base of the ear. If there is any white banding hair, more than likely this black and silver miniature schnauzer will fade.
Also when your black and silver miniature schnauzer puppy starts going through puberty, you could start see bands of white hair come through. Once they go through this stage of life. You will stop seeing this.