Hanne, Marthe, and Klaasje are all set for their first tour, but Marthe notices that the colors of the rainbow have suddenly disappeared. Without the beautiful colors, K3 cannot put on a cheerful show. With the help of Captain Space, K3 tries to get the colors back from the inhabitants of the planets Amoria, Smilus, and Njammie. But that requires a lot of love, fun, and energy...Will K3 succeed in bringing all the colors of the rainbow back together?