Like I said above, there are many different שיטות and מנהגים in this area, and each person should make their own consultations.I have heard that some people don’t consider the Silkie to be kosher because they have 5 toes and dark skin. I think that nowadays some people would consider any chicken that isn’t the Cornish cross to be non kosher, because they are so accustomed to white skinned birds. I’ve eaten Silkie and Silkie mix chickens, they taste like the other chickens I’ve raised for meat.