Guardians of the Galaxy introduced the Power Stone to the Marvel Cinematic Universe. One of the six Infinity Stones, it grants its holder immense power and energy. However, while the stone is purple in its appearances in Guardians, Avengers: Infinity War and Avengers: Endgame, it was originally supposed to be a different color.
During a quarantine watch party of the first Guardians film, director James Gunn revealed that the Infinity Stone the movie was initially planning on using was red. According to Gunn, the color was changed to purple in post-production after Marvel decided that Thor: The Dark World would utilize the Reality Stone, which is red.
Gunn also noted that Marvel did not have its final plan laid out for the Infinity Stones when Guardians was filming back in 2013. It was only during post-production that Marvel figured out where the rest of the Infinity Stones would show up. And just in time, too. Thor: The Dark World released in November 2013, just a month after Guardians of the Galaxy finished filming
Directed and co-written by James Gunn, Guardians of the Galaxy stars Chris Pratt, Zoe Saldana, Dave Bautista, Vin Diesel, Bradley Cooper, Lee Pace, Michael Rooker, Karen Gillan, Djimon Hounsou, John C. Reilly, Glenn Close and Benicio del Toro.
Director James Gunn revealed that Guardians of the Galaxy nearly featured a different colored Infinity Stone.