I saw a limited screening of this at a local theater last night, and was absolutely blown away. They've taken some of George Wyler's original, unused Technicolor footage put together in his 1944 "Memphis Belle" documentary and updated it. The B-17 footage is spectacular, and unlike anything I've ever seen before.
It'll be coming out on HBO before too long.
https://www.hbo.com/documentaries/the-cold-blue (https://www.hbo.com/documentaries/the-cold-blue)