Songfacts®:

• "Rainbow" was the first song I wrote for this record. I was in rehab for my eating disorder. I was sitting on the floor, and I had begged the head of the rehab to let me have a keyboard for one hour a day, and finally she relented. And for that one hour a day I played and wrote "Rainbow." "Rainbow" was just my promise, my letter to myself that things would get better. It was my mantra, because at the end of a storm comes a rainbow."
• The title track to Kesha's third album, "Rainbow" was the first song she wrote for the set. She composed it (after begging the staff for a keyboard) while she was in rehab for an eating disorder. "'Rainbow' was just my promise, my letter to myself that things would get better," she told NPR. "It was my mantra, because at the end of a storm comes a rainbow."
• The rainbow image is an important one for Kesha, who finds herself coming out of the dark:
  
  I used to live in the darkness
  Dress in black, act so heartless
  But now I see that colors are everything
  
  She explained: "For the past couple of years, color has been symbolic of hope for me. I don't think it is a coincidence that it's also symbolic for the LGBTQ community, a sign of freedom to be yourself and celebrate who you are no matter what anyone else thinks. I have been trying to bring more color into my life because that light brings me more happiness and more joy, and it makes me feel more youthful and more childlike. I want to reconnect with that part of myself."
• Ben Folds produced this song and worked up the orchestral arrangement with Kesha. Using her piano-and-voice recording as a demo, they recorded it with a full orchestra in the biggest room available at Capitol Studios in Los Angeles. "Ben wanted me to feel that I was worthy of commanding such a room with my voice," she said. "His belief in me and encouragement over the past few years has really helped me so much in becoming confident in myself and my voice. It was a big step for me to say, 'let's just go for it,' and record live with an orchestra, because it's so different from how I have made music in the past. It was one of the most beautiful experiences of my life."
• The video is made up of footage Kesha's brother, Lagan Sebert, shot while they were recording the song. The vocals used in the song are from the takes seen in the video.
• One of Kesha's favorite lines in this song is:
  
  What's left of my heart is still made of gold
  
  "I know giant pieces of my heart have been held captive in the past," she said. "But not anymore. And what's left is f--king pure gold and no one can touch that."
• Kesha spent a lot of time listening to the Beach Boys album Pet Sounds when she was making Rainbow. She placed this song as Track 8 because that's where "God Only Knows" falls on Pet Sounds.
• Kesha explained during an interview with Elvis Duran on July 18, 2017 what inspired the album title.
  
  "The reason I wanted to name this record Rainbow is because I kind of associate healing with kind of going back to my childlike mind, before I got all twisted and turned and beaten and heartbroken and all those things," she said. "Everything was magical and I didn't understand it. The world was so big and beautiful, and I trusted everyone and everything, and it was just so perfect and wonderful."
  
  She continued, "I've done a lot of healing. I kind of reference that a lot. What's left in my heart is still made of gold, you know? You heal what you can and keep going."