Silver pied is a pattern mutation not a split mutation from all i have read about they can not be split , they are a combination of the pied and white eyed gene working with the white gene
So if someone tries to sell you a dark colored peacock and tell you they are split to silver pied and you can get a silver pied from them ,walk away from that one if you are wanting silver .
This is one reason i have kept so many whites and pieds from my white hens and another reason i am purchasing IB silver pieds on my Florida trip so i will have pieds, white eyed, silvers, blues and whites pop up in my flocks so i may offer a wider variety without getting into colors like bronze ,cameo ,etc,etc, while i love all these beautiful colors they would not work in my flocks as i do not want to mix them in my flocks, i am trying to stay with IB variates only