WARNING: The following contains spoilers for Strange Adventures #4, by Tom King, Mitch Gerads, Evan "Doc" Shaner and VC's Clayton Cowles, on sale now.
In 2011, DC relaunched its entire line of titles with a new, streamlined continuity. Dubbed the New 52, this relaunch would modernize the origins of many characters, giving them fresh starts along with new costumes. Such was the case for Adam Strange, who first appeared in this new timeline in June 2014 as part of the cast of the ensemble book Justice League United.
Adam Strange has always been known for his throwback costume that earned him a reputation as a superhero from a bygone, science-fiction era. With his simple red costume, jet-pack, and silver helmet, Adam Strange was a space explorer of two worlds. However, that was changed for the New 52; the character's legacy was honored, but his costume received a modern upgrade that would appear throughout Justice League United, right up until its cancellation with issue #16. However, Adam Strange's New 52 costume made a brief return in Strange Adventures #4.
Strange Adventures is a book divided into two time periods. In the present day portion of the series, Adam Strange has been accused of murder, and it's up to Mister Terrific to solve the crime and prove whether or not the space-faring superhero is guilty. The other half of the book takes place in the past, and it chronicles Adam's early adventures on the planet Rann, where he earned his reputation as a heroic warrior. Terrific is trying to find the truth, located somewhere between fact and fiction.
In Strange Adventures #4, the past segment of the book shows Adam Strange transported back to Earth just as he was about to engage in a massive battle between the Rannians and the Pykkt. Forced to wait for the next Zeta Beam to take him back to Rann in several days, Adam explores other options to get off-world faster. After Hal Jordan turns him down, Adam journeys to the moon and asks Superman to fly him to Rann. It is during this interaction that the superhero is seen wearing his New 52 costume.
The costume is obviously the one Strange wore in Justice League United, with the same modern design and color scheme as well as the red visor.
This means that Adam Strange's New 52 costume is still canon in the character's DC history. With DC Rebirth and the restoration of the proper continuity following Doomsday Clock, it can sometimes be unclear what parts of the New 52 are still valid. Now, thanks to Strange Adventures #4, we now know Adam Strange's time with the Justice League United still occurred to some degree.
In the 2014 series, Strange joined such superheroes as Animal Man, Green Arrow, Martian Manhunter and Supergirl to form a new Justice League team with a focus on matters of cosmic importance. Strange Adventures confirms that those adventures are still a relevant part of the history of Adam Strange.