In a recent interview with the visual effects team at ILM, it was revealed that the color change for Bruce Banner’s alter ego would’ve happened during the Hulk vs. Hulkbuster scene.
“Initially, Hulk was actually planned to turn grey when he’s angry Hulk in the Hulkbuster sequence but hey, everybody wanted the green guy,” Wired reports. “So, in the end, ILM just changed his eyes to make them look more sullen when he’s under the control of Scarlet Witch.”
Well, that’s a bummer, I would have loved to have a grey Hulk up on the screen also. Maybe next movie….