The Reluctant Dragon (movie)
The first third of the movie is in black-and-white.  The last two-thirds are in Technicolor.  Most of the movie is live-action.  There are four short animated parts. There is black-and-white part with Casey Junior from Dumbo.  There are three Technicolor cartoons: Baby Weems, Goofy's How to Ride a Horse, and The Reluctant Dragon.  The Reluctant Dragon is based on Kenneth Grahame's book of the same name.