Grey Hulk Was Originally Supposed to Appear in AVENGERS: AGE OF ULTRON
A behind-the-scenes video for Avengers: Age of Ultron was released over the weekend that focused on the what went into bringing the Hulk to life again on the big screen again. There’s a lot of great information, but one of the most intriguing bits included the fact that at one point during the movie the Hulk was originally supposed to turn grey.
The plan was to have Hulk turn grey when he was under Scarlet Witch’s spell. So during that whole sequence of him fighting Tony Stark in his Hulkbuster armor, and destroying the city, he was supposed to be grey. There’s no reason given as to why they didn’t ultimately go that route, but it would have been pretty awesome to see the grey Hulk make an appearance in the MCU. I guess the studio opted to keep him green so the color change didn't confuse general audiences?
Pop! even released a grey "Savage Hulk" vinyl figure for the movie, so that must have been the plan for awhile.