This 4k restoration can be seen in NFT1 and NFT3 on the extended run for this film at BFI Southbank. You can find all the details here.
Here is John Ellis's superb analysis of the film from Ian Christie's book 'Powell, Pressburger & Others.
Chicago Reader review:
This enduring 1946 Technicolor fantasy by Michael Powell and Emeric Pressburger began as a propaganda piece meant to cement wobbly British-American postwar relations, and some of that theme survives, notably in the climactic trial scene set in heaven. But the rest is given over to a delirious romanticism, tinged with morbidity, mysticism, and humor. David Niven is the British fighter pilot who misses his appointment with death, falling in love with a Wac (Kim Hunter) on his borrowed time. Powell had more and bigger ideas than any other postwar British director: his use of color and bold graphic images is startling and exhilarating, as is his willingness to explore the subsidiary themes of Pressburger's screenplay, never sacrificing creative excitement to linear plot. And yet, for all its abstraction, the film remains emotionally specific and affecting. With Roger Livesey and Marius Goring.
Here (and above) is the opening to the film.