In the Marvel Cinematic Universe, the Infinity Stones have appeared throughout the franchise, dominating the central plot line concerning Thanos and his imminent threat for almost an entire decade. The stones’ abilities were demonstrated with every subsequent film in which they appear, culminating in Avengers: Infinity War and Avengers: Endgame, in which all the stones were used at once, to both kill untold trillions of people and bring them back from oblivion. But the Stones of the MCU aren’t exactly the Stones of the comics – they’ve changed considerably.
Each Stone is revealed to be artifacts that the main characters were pursuing – and most of the time, the heroes didn’t even know the object in question was an Infinity Stone. For example, the Aether in Thor: The Dark World was the Reality Stone, but with a changed form; the Tesseract seen in Captain America: The First Avenger and The Avengers was the Space Stone; the jewel in Loki’s scepter was the Mind Stone, and so on. When Marvel Studios premiered Iron Man in 2008, the writers certainly didn’t know that Thanos would appear ten years later.
But astute viewers will notice that the Stones in the films are colored different than the comics. The original Power Stone was red, but it’s purple in Guardians of the Galaxy and in all subsequent films. Director James Gunn explained that “…the Power Stone is purple because the Aether already took red. And it’s a better colors for GotG.” This explains why the Stones are colored differently – the various powerful items were retroactively confirmed to be Infinity Stones. But around the latter third of the MCU, the Stones in the comics changed as well.
In New Avengers #3, the old Infinity Stones were changed to match the colors seen in the films. This was accomplished in the Marvel Legacy relaunch through the actions of Franklin Richards during the 2015 Secret Wars event. By that time, the colors of the MCU stones were known, so this was a determined effort to synergize the comics with the universe of the films; Marvel undoubtedly did not want to confuse new readers (motivated to buy comics after seeing the movies) with a green Soul Stone instead of an orange one, for example.
Marvel has taken great pains to make sure the universe of the comics lines up with the universe of the films. This includes relaunching the Eternals in time for their 2021 film, writing Kang the Conquerer as the villain in upcoming titles, and reviving the Guardians of the Galaxy after their newfound popularity. Considering all these moves, it makes complete sense that, thanks to Thanos in the MCU, the Infinity Stones would change their colors to match their counterparts on the big screen.
