The red color shift is well known (though the first time I saw mine do it, I nearly lost it in a major grillfella geek out).
Regular
Heated up (beside the red gasser, which curiously doesn't change color
I wouldn't have believed its the same grill!
Then, in Idahawk's Yellow Kettle thread, he shows that the yellows change too, which I thought was really cool and makes me want one of those. So what else changes color? Pics would be great. I can only confirm that the C&B grey does not.