Originally, Stan Lee wanted the Hulk to be grey, but, due to ink problems, Hulk's color was changed to green. This was later changed in the story to indicate that the Grey Hulk and the Savage Hulk are separate personalities or entities fighting for control in Bruce's subconscious. The Grey Hulk incarnation can do the more unscrupulous things that Banner could not bring himself to do, with many sources comparing the Grey Hulk to the moody teenager that Banner never allowed himself to be. While the Grey Hulk still had the "madder he gets, the stronger he gets" part that is similar to the Savage Hulk, it is on a much slower rate. It is said by Leader that the Grey Hulk is stronger on nights of the new moon and weaker on nights of the full moon. Originally, the night is when Bruce Banner becomes the Grey Hulk and changes back by dawn. In later comics, willpower or stress would have Banner turn into the Grey Hulk. During one storyline where he was placed under a spell to prevent him turning back into Bruce Banner and publicly presumed dead when he was teleported away from a gamma bomb explosion that destroyed an entire town, the Grey Hulk adopted a specific name as Joe Fixit, a security guard for a Las Vegas casino owner, with the Grey Hulk often being referred to as Joe after these events.