We only saw the black suit in a deleted scene in the theatrical release.
Zack Snyder took to Vero today to show the world how Henry Cavill’s Superman was supposed to look in the original cut of Justice League, dubbed the “Snyder Cut” by fans.
The suit was seen prior to this reveal only in a deleted scene released alongside the film in the DVD and Blu-ray special features, but was not included in the main film at all.
This Instagram post by The Cultured Nerd shows Zack Snyder’s Vero post of Henry Cavill in the black suit with the caption “My Superman”.
Zack also made it clear to fans in the comment section that Cavill wore the black suit throughout his version of Justice League, saying:
“I love them both but the blue one is where he must end up after a Journey”
The post below shows several of Snyder’s replies to fans comments on his Vero post:
So there it is: Superman was only meant to wear the black suit in the Snyder Cut of Justice League, and we would have seen the blue suit again further down the line if Zack had been able to complete his planned 5 movie story arc.