Colors of the Heart is the fourth single released by the Japanese rock band Uverworld. It was released on May 17, 2006. The limited pressing which was also released on the same day contains a DVD with the opening sequence for the title track shown in the anime series, Blood+ as well as a sticker with the illustration from the anime's character designer.
The single's title track, Colors of the Heart was written and composed by Takuya∞, with lyrics assistance by Alice ice. The composition was co-arranged by the band and Satoru Hiraide. It was also produced by the band members themselves, Chieko Nakayama and Satoru Hiraide.
The 3 tracks of the single are also available for download as a Chaku-uta(着うた?) for mobile phones in Japan.
The single entered the Oricon charts 15 times while the single's peak ranking was at 3rd.