Silkies are a little bit different. With their black skin you will not be able to see red. Silkie hens typically have a small comb and the bearded ones usually have real tiny wattles. The non-bearded ones usually have small wattles.
My silkie hens have started laying anywhere from 6 months to 8 months of age.
I am not sure about the light. I live in FL and all my chickies lay year round. You can try letting them go a little longer and see if they will start laying and if they don't you can try a light then. Is it getting real cold there yet?
I recently read about the variety of combs in the Murray McMurray Hatchery catalog/magazine. There are at least 6 types of combs they did picture it on page 6 of the 2008 catalog. But I'm not sure about what the size and color does mean. I have some hens with large red combs that are not laying yet. One with a large red comb is laying, but the others are not. The hen with the largest comb hasn't even started laying any eggs yet. Then one RIR hen with a small-to-medium light red comb is already laying for almost a week now. I'm still trying to find more info myself. Good luck with your hens.