Why is my Leghorn's comb turning blue? And cold?

[@~rosecityfarmgirl~@]

The back end of my 1 yr old White Leghorn's comb looks like it may have been injured in the past, as it finishes in a square shape instead of a taper. Since I got her 2 months ago, the last inch or so has been bluish purple. It only went red after I gave her a hot bath, and has since returned to this odd colour. I felt it while holding her the other day, and while the rest of the comb is warm, the blue part is cold. Is this a lack of circulation? What could cause this? Should I be worried for the winter?
Thanks!

 

[ChickenCop]

You are correct on lack of circulation. On large combed roosters I always keep some vaseline in the coop to put on there to stop frostbite.