Rainbow Brite (1984)

On another planet, a girl called Wisp discovers an end to the universe's dark times and becomes the keeper of color. Thus her name changes to Rainbow Brite. As she battles silly villains like Murky and Lurky who prefer gray, Rainbow makes friends with many creatures. Some are other kids who want to help keep everything bright, others are animals such as the egotistical horse Starlite and the quivering sprite Twink. Only one person on the planet Earth knows of Rainbow Brite, her best friend Brian. When things go wrong in our world, all he has to do is use his rainbow key and ask Rainbow Brite for help.