I once again require your help in locating a certain film.

This film, which may be based on a book, is about a boy who is turned into an anthropomorphic donkey. I saw this part of this film on an educational film about 70s and music, where a song was played over it. It could be made between the late 50s and early 70s.

Many parts of this film were still frames with animation over it, like the Donkey boy sleeping and sparkles surrounding him. The film looks like it was colored with paint as well. Near the end, the Donkey grew fairy wings and danced with a fairy, where the animation became white lines over a black background.