Clearly, gamma-rays have woven their way through the lore of the Marvel Universe in comics, movies, cartoons, and video games, but when Stan Lee and Jack Kirby created the Hulk back in 1962's The ...

The Hulk is best known for getting stronger when ... the gamma-powered mastermind known as the Leader used a combination of gamma rays and cosmic energies to transform Ross into his crimson ...

The cosmic rays portion of the process made Ross turn red and not green, as it superseded the gamma part of the equation. The Red Hulk’s powers are nearly identical to those of the Hulk.