Haimura Kiyotaka Artbook rainbow spectrum: colors (『灰村キヨタカ画集 rainbow spectrum:colors』, Haimura Kiyotaka Artbook rainbow spectrum: colors?) is the first artbook by Toaru Majutsu no Index illustrator Haimura Kiyotaka and was released on February 28, 2011. It contains a collection of art from Haimura's light novel illustrations. The art book incorporates both color pieces and monochrome works in chronological order from Toaru Majutsu no Index, with shorter sections for other works like Maid DEKA and Sprite Spiegel. It also includes an interview, a tutorial, and an exclusive original short story written by Kamachi Kazuma "Toaru Majutsu no Index SS: Love Letter Competition".
Featuring a new illustration by Haimura for the short story, the story follows the aforementioned letter that was sent by Kumokawa Seria to be given to Kamijou Touma as it changes hands between various characters from the series.
- The characters used for Haimura Kiyotaka's name were 灰村キヨタカ at the time of release.
- 灰村キヨタカ画集 rainbow spectrum:colors 大型本 from Amazon Japan (Japanese). Retrieved on 2014/4/10.