Color process
Does anyone know what process would have been used to film the color scenes in Ivan the Terrible II? I understand that at least some of the film was made using captured German film stock, which may be the explanation of how a color film was shot in the USSR in wartime. I am also guessing that the manufacture of ordinary film stock in the USSR may have been based on processes acquired from Western companies in the 1920s or 1930s.
Note that when the film switches from black and white to color, it also abruptly switches from brilliantly lit to quite dark, as if Eisenstein used the same lighting for the much slower color film as he did for the black and white film. He must have been aware of the difference. Perhaps he used it deliberately to give the color scenes more of a film noir look.
Finally, could it be that in some of the film, particularly the banquet scenes involving the playlet derived from the Book of Daniel, Eisenstein was influenced by Japanese kabuki theater?