An anonymous painter. However, she paints using colors. Yes, actual colors. In other words, she paints the world as it truly is. There is another reason her paintings differ from others besides the use of color: one can enter them. The paintings she creates with color stimulate the five senses, creating the illusion of actually stepping into a world of color within the canvas. She spends most of her day secluded in an underground atelier, painting year-round. Consequently, even at the Color Research Institute, only the Director and Deputy Director know her face.

Dr. Hue. Deputy Director of the Douter-affiliated Color Research Institute. He has a foul mouth and a poor attitude, but his skills are top-notch. Despite his demeanor, he seems to respect Dr. Shikisai in his own way.

Dr. Saturation. The energetic member of the Color Research Institute. Always cheerful, she keeps everyone's spirits up. Her research skills are decent.

Dr. Brightness. The resident slacker of the Color Research Institute. He often goes missing and gets scolded by Dr. Shikisou or Dr. Hoshoku. He is highly skilled when he actually works.

Dr. Complementary. An apprentice girl at the Color Research Institute and the resident klutz. She frequently reveals her clumsiness but works hard with everyone's encouragement.