Marvel Comics’ mega-strong, most-in-need-of-anger-management character the Hulk is best known for being green. Originally he appeared as grey, just as his creator Stan Lee intended. When a printer error turned him green, Lee decided to go with the flow.
The Hulk has returned to grey occasionally over the more than half century since he first appeared. He has also sported different colors from time to time. In the end, however, he is iconically green, and we can just hope he doesn’t get very, very angry about that printer’s mistake.