Rainbow Brite and the Star Stealer

Rainbow and her magical horse Starlite travel from Rainbowland to Earth to bring about spring. They face Stormy, a rival who controls Winter, and Rainbow defeats her to press on. After their skirmish, they meet Brian, the one boy who can see them, and begin their Earth-based mission to awaken the seasons.

On Earth, Rainbow tries to start spring, but her power weakens and Winter lingers. Brian senses that humanity is losing hope, and Rainbow herself feels puzzled by the stalled season. The team decides to return to Rainbowland to seek guidance and plan how to restore Spring.

Back in Rainbowland, On-X arrives—a robotic horse with rockets for legs—to deliver news that Orin, the leader of Spectra, has gone missing. Rainbow agrees to undertake the mission to find Orin and defend Spectra from threat. The urgency sets the stakes for the quest ahead.

Rainbow learns that Spectra is dimming because a massive net is being woven around its surface. The net is designed to let a selfish Dark Princess steal Spectra and tow it away with a giant spaceship. The enslaved Sprites are forced to weave the net under control of Glitterbots.

Dark Princess's plan becomes clear: she intends to steal Spectra, the universe's greatest diamond, to power her realm. Rainbow encounters Krys, a skeptical Spectran boy who believes he can handle the princess by himself and dismisses Rainbow as a 'dumb girl'.

Krys is persuaded to join forces after Orin urges them to work together to stop the princess. He agrees to combine their powers with Rainbow to defeat the threat and save Spectra.

Murky Dismal and his bumbling assistant Lurky revel in the gloom of Spectra's dimming and actively obstruct Rainbow's mission. They also attempt to steal Rainbow's color belt for themselves, complicating the group's plan.

Rainbow and Krys infiltrate the Dark Princess's castle to confront her, but the princess traps them after stealing Rainbow's belt. Starlite remains nearby, ready to help as the situation grows dire.

Starlite retrieves Rainbow's belt, allowing Rainbow and Krys to escape the dungeon. With their powers renewed, the duo prepares to confront the Dark Princess and end her scheme.

The Dark Princess uses her crystal to create a vortex, sending Rainbow, Krys, Starlite, and On-X to a prison planet. Starlite is captured, Rainbow is attacked by humanoid lizard guards, and Krys and On-X are taken to Zombo's castle.

On the prison planet, Rainbow meets Orin who explains that the princess's power comes from her crystal and that they must destroy it by combining their powers. Orin urges them to work together to save Spectra.

Rainbow and Krys confront the Dark Princess in the throne room and destroy her power crystal, ending her control over Spectra. Murky and Lurky crash their ship to disrupt the duel, and the princess attempts to crash into Spectra, but Rainbow uses her rainbow to deflect the ship, causing the explosion that ends her threat.

Enslaved Sprites are freed and destroy the net, allowing Spectra to radiate its magical light once again. On Earth, spring finally arrives as life returns there, and Rainbow returns to Rainbowland where friends are back to normal.