What could cause this purple color on my chickens comb edges?

[kucukti]

Yesterday I noticed that one of my chickens comb started to turn purple from edges.
There isn't any other sign of a disease for her. I have 15 chickens that I look after.They are all well.


What could cause that color change on chicken's comb?
Can you please help me about this. I don't want to loose my chicken.

Sorry for my bad english.

 

[TWK777]

If the back of the comb is dark, it might be stress or hormones. If the darkness moves up the comb it is a sign of a serious heart or lung problem. I had a hen die recently, and most of here comb was dark purple. what breed is it?

 

[limited25]

Our rooster's comb will turn purple on the edges like that when he is stressed (like when he is separated from his hens for a while ... for good reason). When he is put back with them it immediately turns back to bright red.

Oh, and