Best friends Kishiko, Shellnelle, Harmonique, Riviera and Jordie are granted magical color change power that they must use to save their fabulous underwater city.
With Orra's tail drained of color, the girls are on their own. Will their powers be enough to finally put a stop to Morra's color-draining jealousy? Will they be able to save Mermaid day and Mystic City?