This 72-year-old cartoon is about fun-loving elves who drink bottled sunshine and a neighboring tribe of truculent, belicose, heliophobic grumps (their mantra: "We're happy when we're sad") who want to kill the happy elves with chemical weapons.
Finally, the happy elves resort to chemical warfare of their own -- they dose the sourpusses with sunshine juice and turn them into happy elves. (Of course, this violates Timothy Leary's First Law of the Molecular Age: "Thou shall not alter the consciousness of thy fellow man.")
The print quality of the video is poor. Amazon sells a DVD compilation of Van Beuren Studio cartoons with "The Sunshine Makers" on it, but I haven't seen it so I don't know if the quality on it is any better.