Some Silkies that are pure can hatch with four toes.
The fact that one of the parent was not pure makes it a cross breed having some traits of either parent.
Some chicks can be Silkie feathered... that doesn't make them a Silkie. They may be Silkie cross.
Even Silkies that don't have the correct number of toes or skin color can still be pure Silkie... Just not quality as far the standard of perfection goes.
In this instance... since the hen IS Silkie and the cock is a Silkie cross... I might expect 50% of the chicks to be Silkie feathered.
Especially in project colors like paint they can skin color that shows up pink.
The simple answer to your question according to your stated facts is... your chicks are 3/4 Silkie (in theory)... but NOT pure.
Any Silkie with 4 toes... gets CUT from my breeding program. It is not acceptable when breeding to the standard of perfection. Since ALL my breeding stock ARE pure... I would sell them as PET/laying quality Silkies... not for showing or breeding.
Skin color is JUST skin color. In cross breeds you can get any. Having a correct skin color of a particular breed does NOT make a chicken that breed.
I know this is coming out very matter of fact like... But I promise is meant to be friendly and helpful!
Also... (cute birds BTW

) That rooster has a straight comb as well as the hen in the pic. Silkies should have a walnut comb. They can be bearded or non bearded, but ALL should have a crest and blue ear lobes.
IF that picture is of the hen and roo that produced your chicks... the hen is ANYTHING but a Silkie (maybe cross at best). She isn't Silkie feathered, no feathered legs, no crest, wrong skin, shank, lobe, and beak color.
Anyways, I don't mean to pick anyone apart... they are lovely birds regardless of actual heritage. But I hope this helps to answer your question.
Congrats on your hatch!

