Through the Dragon's Eye (1989)

Jenny, Amanda, and Scott are painting a mural on a wall in their school's playground. Suddenly, the dragon in the mural winks at them and begins to come alive. The dragon invites them into the mural and the children enter to discover a land called Pelamar. Gorwen the dragon tells them that the land is dying because its lifeforce, the Veetacore, broke apart. The pieces were collected by the Keepers, but they aren't sure how to put them back together. The kids agree to try and figure out how to fix the Veetacore, which leads them on a journey through Pelamar.