My sister's Silkie, plus the other two silkie roosters I have came from a Breeder of Show Quality Silkies.
Also, Buff Silkies are also of Partridge Base, instead of Wheaten, which also maybe the explanation for the coloration.
With silkies, alot of the times, especially with partridge, the chicks will either have, or lack any partridge pattern.
Partridge Silkies, chick down can vary like this: Stripey Partridge Pattern, Solid yellow, yellow with some markings, Brown, or pure black.
My sister's partridge silkie...