The third and final trailer for Batman V Superman: Dawn of Justice - marks the first time that the world's finest heroes - Batman (Ben Affleck), Superman (Henry Cavill), Wonder Woman (Gal Gadot), Flash (Ezra Miller), Aquaman (Jason Momoa), and Cyborg (Ray Fisher) - will unite in live-action on the big screen.
Of course, with a movie like this, any morsel of information is shared throughout the internet and each detail is analyzed for any sort of plot revelation - and that includes the progression of visual effects throughout post-production. The film's early trailers featured impressive CGI work, but the VFX team clearly wasn't finished yet - as is the case with every other blockbuster movie - and so, over time, things have changed, such as the sky's color in the movie's presumed third act.
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The to finish Snyder's vision for the film.
Aside from whose decision it was to change the movie's color, and disregarding the fact that details tend to change during the post-production process, what's interesting about the red color scheme is its connection to the comics. While some people may assume that the addition of red skies in the movie means the studio is borrowing elements from DC Comics' 1985 crossover event, Crisis on Infinite Earths, thus indicating a potential reboot within the cinematic universe, what's more likely is that Snyder wanted to up the stakes for climactic battle that also adapts details from the comics.
In certain story arcs - both in the comics and in animated shows - Darkseid and his Apokoliptian forces attempt to terraform Earth into a new Apokolips. For instance, in an episode of Superman: The Animated Series, Darkseid's henchmen disable a nuclear power plant's cooling system, thus causing a nuclear meltdown, which, in turn, overloads the planet's volcanoes and turns the sky red. That seems like the most likely reason for the red skies in the trailer (and the movie). After all, Superman's Kryptonian powers.
What's interesting, though an unlikely connection to the film, is that fans of DC Comics use the term "red skies" as a reference to comic book issues that minimally tie into an overarching crossover event (think: Supergirl's Invasion! crossover episode from season 2). While that may not be what's happening with the movie, we can't be sure until Justice League hits theaters next month.
