Black Widow has a new white costume - and it hints at a potential Winter Soldier appearance in her solo movie. Marvel Studios used D23 as an opportunity to unveil the new white costume for Black Widow, with footage showing Natasha Romanoff wearing this suit while in battle with Taskmaster. To the delight of attendees, the Black Widow white costume was actually on display at the Marvel booth.
The D23 Black Widow footage confirmed that Scarlett Johansson's character will wear this for a very practical reason. The fight scene with Taskmaster was set in some sort of snow-covered environment. Natasha Romanoff is essentially the MCU's greatest super-spy, and she's an expert at covert operations. Her usual black costume would stick out like a sore thumb, but an all-white catsuit would make her incredibly hard to spot in the snow.
The costume is also a visual nod to Black Widow: Deadly Origin, a comic written by Paul Cornell in 2010 that attempted to streamline Black Widow's comic book backstory after her MCU debut. Flashback scenes saw Natasha Romanoff don an all-white catsuit on missions in the USSR - and she was wearing this outfit during early interactions with both the Winter Soldier and the Red Guardian. Given David Harbour is set to play Red Guardian in Black Widow, it looks as though Deadly Origin could be a major source of inspiration for the film. If so, the white costume may hint that the Winter Soldier will make an appearance as well.
Of course, the relationship between Black Widow and the Winter Soldier may be very different in the comics. There, the Winter Soldier was brainwashed into working for the Soviet Union rather than Hydra, and in fact he and Natasha Romanoff were sweethearts. In contrast, in the MCU Black Widow claims to have only limited knowledge of the Winter Soldier. In Captain America: The Winter Soldier, Natasha told Steve Rogers of one encounter with Bucky, whom she described as a "ghost." She recounted a mission in 2009 in which she was escorting a nuclear engineer out of Iran, and failed because of the Winter Soldier, who shot a bullet straight through her. However, it's worth noting that Natasha is a secretive person, and it would be quite like her to only tell Captain America what she thought he needed to know to take the Winter Soldier seriously. Certainly that was hinted at in Captain America: Civil War, when Natasha fought a brainwashed Winter Soldier. "You could at least recognize me," she complained as he throttled her, hinting at a deeper history between the two.
It's possible that Black Widow will finally reveal the truth. Although the film is set shortly after the events of Captain America: Civil War, it's generally expected to include a number of flashbacks; there have been hints it will reveal the truth between Hawkeye and Black Widow's legendary mission to Budapest, for example. If there are indeed flashbacks, there may well be further clues explaining the true past relationship between Natasha Romanoff and the Winter Soldier.