Rainbow Brite, [Bettina Bush], and her radiant horse Starlite set out from Rainbowland to Earth to help usher in spring. On their arrival, they cross paths with Stormy, [Marissa Mendenhall], a fellow magical girl who commands Winter with her own steadfast horse, Skydancer [Peter Cullen]. Stormy isn’t ready to give up the chill of the season, and a lively contest of wind and light unfolds as Rainbow and Starlite race to claim the right to warmth. Along the way, they meet the inhabitants of Earth, including Brian, [Scott Menville], the only boy who can truly see them, whose hope for a brighter season mirrors that of the world itself. Rainbow and Starlite’s early efforts falter as Winter stubbornly lingers, leaving Brian to sense that humanity’s spirits are flagging in the wake of the fading spring. Hope hangs in the balance, and the quest continues.
A new visitor arrives to complicate matters: On-X, [Pat Fraley], a strange robotic horse with rockets for legs, bearing urgent news. He brings word that Orin, [Les Tremayne], the enigmatic leader of Spectra, has disappeared. Rainbow accepts a mission that leads them toward Spectra, a vast world already dimming as a colossal net begins to creep across its surface. The net is being woven by the Dark Princess, [Rhonda Aldrich], a self-centered ruler who longs to haul Spectra’s legendary gemstone—the universe’s greatest diamond—back to her own domain aboard a mighty spaceship. The native Sprites, enslaved by Glitterbots under the princess’s command, are forced to weave the web that traps their world. Twink, one of the Sprites portrayed by [Robbie Lee], lends a spark of courage even as the danger grows.
To build their alliance, Rainbow teams up with Krys, [David Mendenhall], a Spectran boy who believes he can face the challenge on his own—until Orin urges him to work with Rainbow and Starlite. Orin explains that their only chance to defeat the Dark Princess lies in combining their powers rather than standing apart. As the stakes rise, Murky Dismal, [Peter Cullen], and his bumbling assistant Lurky, [Pat Fraley], revel in the gloom creeping across Spectra and plot to steal Rainbow’s magical color belt. Rainbow and Krys press forward, infiltrating the princess’s castle with the help of Starlite, but the princess traps them after seizing Rainbow’s belt. They escape the dungeon when Starlite recovers the belt, and the Dark Princess—furious at her setback—uses a powerful crystal to unleash a vortex that sucks Rainbow, Krys, Starlite, and On-X into a prison planet.
Sargeant Zombo, [David Workman], captures Starlite while Rainbow faces humanoid lizard guardians who drag Krys and On-X to Zombo’s castle. There, Orin delivers a crucial revelation: Rainbow and Krys must destroy the Dark Princess’s crystal, the source of her power. The duo locates an unguarded path into the palace and confronts the Princess in her throne room. In a dramatic disruption, Murky Dismal and Lurky crash their ship into the chamber, providing Rainbow and Krys just enough distraction to break the Princess’s hold. With the crystal shattered, the Princess races to her ship in a desperate bid to crash into Spectra, but Rainbow’s rainbow shield deflects the collision and sends the vessel plummeting away, exploding in a burst of light.
freed Sprites rally to break the oppressive net that bound Spectra, and Spectra’s own magic returns to life as its people reclaim their freedom. Back on Earth, a warm spring finally arrives, and life blooms once more as Rainbow’s presence helps bring hope back to the world. Rainbow returns to Rainbowland to find her friends restored and their magical balance renewed, marking a hopeful dawn for both Spectra and Earth.
