Silkies have 5 toes, & Fibromelanosis.
This is my Crestless, & single combed LF Silkie pullet. That varies between individual brown layers mainly.
But AustraWhites lay light brown/cream colored Eggs.
Barred Rocks lay Tinted & Speckled, or Cream.
Silkies may lay, White, tinted, cream, light...
So, most likely Silkie Ancestry somewhere in the cross.
My Guess for the crossing for these would be White Leghorn/Barred Rock X AustraWhite/Silkie.
I guess Barred Rock since some Smokey Pearls have ghost barring.
Well, the actual breeds(Multiple), used in the cross for Smokey Pearl's aren't known, since it hasn't been revealed by the hatchery unlike other hybrids.
But some do have Fibromelanosis, so some sort of Fibro breed was used.