I have a pullet whose comb was red and now has yellow on it. Mostly at the base. It seems strange to me. She's seven months old and I'm pretty sure has been laying, although not a lot. I don't know if it matters, but she has a really large comb for a RIR pullet. I've seen other breeds with large combed hens, but my other RIRs are much smaller. She Seems well enough. It's just strange.