Avengers: Doomsday directors Joe and Antony Russo have issued a fresh tease for their upcoming Marvel blockbuster — and even though it's just a single color, fans are still racing to work out what it all might mean.

Over on Instagram, the Russos' official account has uploaded a plain green image, tagged with the official accounts for Marvel Studios, The Avengers franchise, Robert Downey Jr., their production company AGBO Films, and the SXSW London fan event, which takes place next week.

The Russos are no stranger to posting cryptic Instagram teases, having previously posted blurry, black-and-white photos from the Avengers: Doomsday set that fans have analyzed in minute detail. But this image, however, is proving a little more tricky.

Being just a single color, fans are looking to clues based on the shade of green's Hex color values, with many suggesting the numerical code could point to a trailer date, or hint at new information. But there's also general disagreement over what the actual shade of green is, which isn't helping.

"The RGB values of this color are 113, 127, and 91," wrote Marvel fan lorenzocpl, before launching into a tactic fans have previously used to scour for clues in past Marvel films. "If you check those timestamps in Avengers: Endgame, something interesting happens: at 1:53, it's the Natasha and Clint scene; at 2:07, Hulk uses the stones; and at 1:31, the time-travel sequence is happening." It's unclear what this is supposed to mean, however.

On a surface level, this color green is almost certainly supposed to reference Doctor Doom, who wears a green cloak and hood. But surely there's more to it than just that?

"I think Dr Doom is going to be green," wrote one fan. "Shrek will return in Avengers Doomsday," quipped another.

We’ll learn more about Doom when Avengers: Doomsday arrives on December 18, 2026. But could we see him again beforehand? It's worth remembering that Marvel plans to re-release Avengers: Endgame this September with new footage added in.

Image credit: Marvel.

Tom Phillips is IGN's News Editor. You can reach Tom at tom_phillips@ign.com or find him on Bluesky @tomphillipseg.bsky.social