Why did the Hulk become green again? He became grey after mixing the Hulk serum with a blood sample from Captain America, which also resulted in the Hulk problem becomign permanent. But after his failed execution, his next appearance in The Ultimates 2 Annual #1 shows him as being green. Was the rechange a result of being irradiated during his apparent death, or was the grey change temporary?
So Grey Hulk is when he is being selfish and evil, Green Hulk is when he is pissed off and trying to help someone?