Actually, this is my first winter with chickens, and of course, it's the coldest winter on record for our area. My rooster's comb has turned purple on the tips several times, but the color has come back when he warms up. After the last really cold snap when we went down to 5 degrees, I noticed that the tallest tip was black on the end, kind of pale in the middle, but still red the rest of the way down. I thought that was frostbite and that he would probably loose that tip, but it seems to be getting color back.
So, to answer your question, I'm not really sure ...
???
So, to answer your question, I'm not really sure ...