The song was first mentioned in an interview with The New York Times.
|“||While she was in rehab, Kesha wrote a song called “Rainbow” on her tiny toy keyboard. Her mother had always told her that you could tell that a song was great if it could be sung against just one note and still sound good. As she sat singing it against one note, on the floor of the rehab facility, she knew she had something. She imagined “Rainbow” like a great orchestral production, something that Brian Wilson would have done on “Pet Sounds.” She wanted this song to be produced by Ben Folds, who just happened to have friends who could play cellos and violas and kettle drums and the oboe and the flute and the French horn. He called in all his favors, and they rented out the big room at Capitol Records and tried to do the song fast and cheap. He wanted her to stand where Nat King Cole and Frank Sinatra had stood, to understand her importance in the line of musicians that people remember.||”|
Taffy Brodesser-Akner, interviewer
I found a rainbow, rainbow, baby
Trust me, I know life is scary
But just put those colors on girl
And come and paint the world with me tonight