I would like to propose for the comments and opinions of the members of this fine board that the real reason for Welles's meager output after CHIMES AT MIDNIGHT was Welles' inability to work to his full creative potential in color. I say this not to criticize Welles, but to offer a speculatory explanation for one of the central questions of Welles biography. The commercial shift from B&W to color occurred during the CHIMES period; and that masterpiece may have already started to look "old fashioned" to the critics and public of 1965, at least in Welles's eyes, after the fact, when he tried to figure out why his greatest picture got nowhere in the land of his birth.
I get the feeling that Welles was frustrated by color, that he did not feel free with it creatively, and that for him it was an artistic dimunition, not an advance. He is on record as stating his dislike for the medium, especially where acting is concerned. Certainly he tried, with FOUNTAIN OF YOUTH, IMMORTAL STORY, THE DEEP, F FOR FAKE, MERCHANT OF VENICE, THE OTHER SIDE OF THE WIND, ORSON'S BAG, THE MAGIC SHOW, etc., to come to grips with color; there is, in these films, some released, most not, many lovely things, especially in IMMORTAL STORY; but I think I can safely say that none of these efforts reach the sheer expressive power of Welles's best work in B&W. They are Welles lite. B&W film was Welles's medium, and asking him to shoot in color was like asking Albrecht Durer to paint with watercolors. With the shift from B&W to color as a commercially viable medium, Welles may have felt that his paint box had been taken away. He tried to adapt, but knew in his heart that the results were not up to his standards. Thus the "fires", the "stolen soundtracks", the "lost negatives" that have become part of the Welles mythology, and which, are, I believe, a comsummate magician's distraction and sleight of hand.
There is significant evidence that Welles held back DON QUIXOTE, shot in B&W, because he was afraid the public would see it as "outdated". For all of his genius and aristocratic ways, Welles, who once did a tour in vaudeville, never saw himself as anything other than a popular artist - he did not identify with the avant guarde. As he stated in an interview, "you are looking at a man who has spent his life looking for a popular audience." He cared what people thought.
Color photography was also inimical to Welles' preferred shooting method in the latter part of his life: fast, cheap, and on the fly. You can get good effects in color, but it requires more money and equipment. As Greg Toland, and another master, John Alton have shown, you can go to town in B&W with one light. As I have mentioned in another post, it's a pity that Welles never hooked up with Mario Bava, one of the few DP/Directors to have fashioned a genuinely expressionist color style during this period, and who was a true cinematic wizard who could conjure up amazing effects for peanuts.
The creative resurgence that energized Welles in the years before his death may have been caused by nothing more than his realization that B&W, because of films like MANHATTAN, had become commercially viable again. KING LEAR and THE CRADLE WILL ROCK were to have been shot in B&W. I don't know about THE BIG BRASS RING, but I see that one as another STRANGER/DEEP, done for commercial purposes, to keep Oja quiet, and not to be taken seriously. And in the early 80"s, Welles got excited about DON QUIXOTE again. But it was too late...
Anyway, I would love to get some input here.