white in silkies is most often recesive white meaning it takes two copies to show and it is inherited independently of other colors so any color could be hiding under the white, black is dominant over most colors so you would most likely get black with leakage, unless the white is hiding black...
My silkie cross pullet (3/4 silkie 1/4 EE) started laying about 2 weeks ago and I have about 7 of her eggs in my incubator due to start hatching the 15th
I have a silkie x easter egger hen, and a few weeks ago i hatched an egg from her that was fathered by my black silkie rooster sadly its one of the 25 percentile with smooth feathers... oh well at least i know it carries the silkie feather gene