I just saw the coolest thing! I have a Mottled Java, and she got inside the house to say hello, and so I picked her up, noticing how red her comb/face/wattle are becoming and admiring her. I was calmly talking to her and petting her, and the circular area below/behind the ear that was red, turned white. When I started moving around, it turned red again. I calmed her down again and it turned white again. Isn't that cool! Or does this happen to all the chickens? So cool.