When the Spectrum Kingdom gets invaded by the Dull Warriors, Prism is sent to Niji-iro City to find the Precure. While on Earth, Prism meets Kazano Aka, a passionate tennis player who is very popular in her school. Suddenly, Gris appears and creates a Blanko which makes everyone fall into a pit of despair, all except Aka. Prism realises that Aka is only one who has not fell into despair therefore realising that Aka is one of the Precure and gives Aka a Spectrum Pact while telling her to shout "Precure, Magical Spectrum Activation!". Aka then does so and becomes Cure Rosso!
The lead cure of the season. Aka is a very passionate tennis player who has a heart of pure justice. She is also the captain of the soccer team and the top student in food technology. Aka's Pretty Cure alter ego is Cure Rosso, the flame of passion whose theme colour is red.
Akemi is an elegant A-grade student and Aka's classmate at Niji-iro Academy. She is also the captain of the gymnastics team. Akemi's Pretty Cure alter ego is Cure Tangerine, the light of warmth whose theme colour is orange.
A very fashionable girl and head of the textiles club. She can tell which fabric she is touching without even looking at it. Sol's Pretty Cure alter ego is Cure Soleil, the star of peace whose theme colour is yellow
A very shy student of the Niji-iro Academy Gardening Club. However, under all that shyness, is a sociable friendly girl waiting to be free. Her Pretty Cure alter ego is Cure Trébol, the clover of life whose theme colour is green
A very famous idol who goes undercover to school. In her undercover form, she is very shy but outside her undercover form, she is very very energetic. Her Pretty Cure alter ego is Cure Oceano, the water of elegance whose theme colour is blue
A lively, energetic girl who also has a dark past when she was abandoned by her parents. Her Pretty Cure alter ego is Cure Violetta, the crystal of power whose theme colour is indigo.
One of the members of the Tennis and Gymnastics club, Ai is a very elegant girl. Her Pretty Cure alter ego is Cure Rosa, the heart of love whose theme colour is pink
Lavender is a famous model as well as a sweet fun-loving girl. Her Pretty Cure alter ego is Cure Iris, the flower of happiness whose theme colour is purple
Yuki is a klutz however can be smart at times. Her Pretty Cure alter ego is Cure Neige, the snow of future whose theme colour is light blue.
The reincarnation of Princess Pastel of the Spectrum Kingdom after she was defeated by King Embotado of the Dull Warriors. Her alter ego is Radiant Arcobaleno, the radiance of rainbows whose theme colour is white.
The main fairy of the season. She is an intelligent fairy of the Spectrum Kingdom.
Prism's identical twin sister. Unlike Prism, she is a klutz.
The princess of the Spectrum Kingdom. She was reincarnated on Earth as Hikari after she was defeated by King Embotado of the Dull Warriors. Her alter ego was Cure Vistoso, the colorful star whose theme colour was the colours of the rainbow.
Aka's mother and one of the past Precure, Cure Rojo.
- Niji-iro City (虹いろシティー Niji iro shitī?) - The hometown of the cures and main setting of the series
- Niji-iro Academy (虹いろアカデミー Niji iro akademī?) - The school the cures attend.
- Spectrum Kingdom (スペクトラムキングダム Supekutoramukingudamu?) - The homeland of Prism, Gem and Hikari that was invaded by the Dull Warriors.
- Spectrum Pact (スペクトラムパクト Supekutoramupakuto?) - The girls' transformation item to transform into Precure.