I have always loved the look of Disney's 1953 featurette Ben and Me.
Ken Anderson and Claude Coats were art directors, Al Dempster was head of backgrounds. (How lucky can you get, I had the chance to meet and have conversations with all three of them.) I like the film's story treatment by Bill Peet, but I do find the character animation a bit lackluster for a Disney production. The film's visual presentation stands out though in terms of staging, color and backgrounds.
Every mood is depicted beautifully, from serene night scenes to dramatic action.
More on Ben & Me in this previous post: