"Colour My World" is a song written by American musician James Pankow, one of the founding members of the rock/jazz fusion band Chicago. Part of Pankow's "Ballet for a Girl in Buchannon" song cycle/suite, it was recorded for their second album Chicago, also called Chicago II (1970). Terry Kath sings the lead vocal, and Walter Parazaider performs the highly recognizable flute solo.

The song was initially released as the B-side to "Make Me Smile" in March 1970. It was re-released in June 1971 as the B-side to the re-release of "Beginnings"; this second single reached #7 on the U.S. Billboard Hot 100.

"Colour My World" became a popular "slow dance" song at high school proms and university dances during the 1970s.

Chicago continues to perform the song, either on its own, or as part of the Ballet. Since Kath's death in 1978 and being brought back into their set list in 1982, lead vocals were performed by Bill Champlin until 1991, when Robert Lamm took the lead. It has been sung by trumpeter Lee Loughnane since 2009.

...
Wikipedia