at about 00:03:10 on the WP, during the downward shot of Vader’s shuttle entering the hangar, there is flickering around the shuttle. It is most obvious on the bottom edges of the shuttle and on the left side of the shuttle’s central wing.
Also, at 00:04:08, the Stormtroopers’ uniforms have a slightly yellowish tint. This yellow tint is gone in the next shot during the same scene at 00:04:48.