Among the many hints, details and Easter eggs of the various Justice League movie trailers, we're curious about something which may be lurking literally in the background. Specifically, today we're talking about the reddish skies which color many of the trailers' fight scenes.
The phrase "red skies" goes back to DC's foundational line-wide crossover, 1985's Crisis On Infinite Earths. Then as now, it can be used to signal a very specific sort of cosmic event. However, from all we know about Justice League, the odds aren't great that a Crisis is on the horizon (at least not yet). Today we'll explore the development of DC's red skies, to see whether they're more of a red alert or just a red herring.
When DC's writers and editors were planning Crisis On Infinite Earths in the early 1980s, they came up with various ways to tie it into their ongoing series. First was the Monitor, a mysterious figure who spent over two years prior to April 1985's COIE issue #1 popping up everywhere from New Teen Titans to G.I. Combat. Whether readers saw him, his assistant Lyla or just their golden satellite headquarters, their collective presence foreshadowed bigger things to come.
Once Crisis itself was ready to launch, writer Marv Wolfman suggested various other in-story connections. His memo dated November 5, 1984 (reproduced in the "Compendium" volume of Crisis On Infinite Earths: The Absolute Edition) even included a "How To Tie-In With The Crisis" section:
[...] It can be as small a connection as having some manner of natural catastrophe occurring in your book.... Your hero/es solve the problem on the way to their regular story. The first physical reaction on Earth to events in the Crisis is natural disasters and their aftereffects. Even mentioning about unexplained disasters occurring is a tie-in of sorts.
Wolfman closed the memo thusly:
One last note: Because of the structure of The Crisis, I am going to ask that the skies in our books be colored red ... starting with the August books on sale. I haven't asked yet, but this letter is formal notification. If you don't [otherwise cross over], you can have your characters note the reddish hue. Here's hoping for company-wide cooperation.
A few days later, his memo of November 9, 1984 (also reprinted in the "Compendium") described how the red skies, and attendant "red rain," should manifest themselves in comics on-sale in July, August and September 1985. As envisioned by Wolfman and depicted in various degrees in the books themselves, the red skies were just one symptom of the Earth's impending doom. The aforementioned natural disasters, unusual weather and other environmental calamities were supposed to heighten an already-suspenseful mood. In practice, though, the red skies seemed so ubiquitous, and appeared in stories with almost no other Crisis component, that they became synonymous with the bare minimum an ongoing series would have to do to participate in a crossover. This applied not just to Crisis, but to later DC and Marvel events as well.
Perhaps not surprisingly, the crossover which arguably had the least to do with Crisis happened with Wolfman's own New Teen Titans. Complementary scenes in Crisis #9 and NTT #14 showed Nightwing, Jericho and Starfire returning to her home planet for an arranged marriage. Technically it qualified as a crossover; but ironically, it took place after the red skies had disappeared. Moreover, the Losers one-shot (written by Bob Kanigher and pencilled by Judith Hunt and Sam Glanzman) only tied into Crisis inasmuch as it was about a group of obscure DC war-comics characters who died therein. The special itself described how they died in the revised timeline.
Conversely, the "Compendium" lists 50 total issues (representing 15 ongoing series and including the Losers one-shot) which either tied into Crisis On Infinite Earths or were branded as such. Of those, 10 didn't have the distinctive Crisis-crossover cover banner but took place during the miniseries' events. These included Green Lantern #195, which expanded on Guy Gardner's reactivation as a GL (continuing from Crisis #9); Legion of Super-Heroes #16, wherein Brainiac 5 mourned Supergirl's death; and Detective Comics #558, which led into Crisis #2's Batman/Joker scene.
Nevertheless, readers began referring to "red-sky crossovers" whenever an ongoing series only nodded to the event du jour. These sorts of tie-ins merely reminded readers that a big event was happening, without expanding on how it affected the particular ongoing series. In this respect, the red skies were merely window dressing.