Will the head spot method also work on X breeds ? I have BR hens & light Brahma roo. My chicks are still hatching as I type. A couple have very definate head spots & one has the softer edged head spot. Do you think there is a chance this method could be acurite with my chicks? Won't be able to post pics today, maybe tomorrow. Still just curious? BTW : all chicks have the classic BR coloring.