Welsummers are red duckwing, not gold duckwing. That’s why they have so much red.Depends on how genetically close the silvers and golds are to each other. In some breeds, the silvers have no autosomal red (a good example of this would be silver leghorns) and in some the silvers have a lot (like silver cubalayas). And some gold duckwings have a lot of autosomal red (welsummers) and others have less (gold phoenixes).
Golds always have the gene that allows for autosomal red (which is wildtype), if they don’t, then they are lighter.