Luna's farm is usually quiet, but her best friend Barnaby is the silliest donkey in the valley. Barnaby loves getting into trouble. He wears polka-dot socks on his ears and always finds a way to turn an ordinary day into an adventure. When Luna brings out a bucket of bright rainbow paints, Barnaby decides to become an artist. But one splash of green paint lands right on his nose. A-CHOO! A colorful cloud of paint spots flies across the farm, covering the barn, the chickens, and even Luna herself. Will Farmer McDonald be upset by the colorful mess, or will Barnaby's accident become something magical?