Songfacts®:

• Fiona Apple often uses colors to describe her thoughts - she refers to the basic elements of a song as its "primary colors." On this track, she uses color theory as an analog for her feelings, and to describe a relationship that isn't working; two colors mixed together can create a new color, but that color is often gray - far less vibrant than the original. Red is what she sees when she looks upon the relationship, which clearly isn't working.
• This is one of nine songs on the Extraordinary Machine album that was re-recorded nearly two years after it was first put to tape. The original sessions were produced by Jon Brion, who had produced Fiona's previous album When the Pawn..., and had also worked with Aimee Mann and Rufus Wainwright. These sessions were fraught with problems; originally scheduled for release in 2003, by 2005 there was still no album.
  
  Brion moved on to other commitments, the record company pulled funding, and the album seemed dead. It was salvaged when Fiona's friend, the producer Brian Kehew, offered to work with her in a new environment: his home studio. Over the next month, they recorded new versions of the songs, stripping them down for simplicity. Musicians were brought in as needed, which offered a fresh perspective. For this track, Kehew enlisted Jebin Bruni, who was part of Fiona's touring band. In our interview with Brian Kehew, he explained: "Jebin brought a little Casio keyboard with tiny keys, as well as the keyboards we had available. He started playing along with that song, and he started playing this moody, dark, low thing on his Casio that instantly changed the mood. Fiona was there and said, 'I like that.'
  
  And we, at that moment, changed the style of the song to a different, slower kind of languid mood; almost drone-y, but not quite. It now sounds like slow molasses, which is a different kind of feeling than it originally had when the recording was done. But that took it in a new direction just from a keyboard sound." (Here's Brian's full story of making Extraordinary Machine.)
• Taylor Swift wrote her own sanguine song with a similar theme on "Red," which was the title track to her 2012 album.