In April 2011, a splash screen appeared on the band's website, that contained a distorted Autobot image and a snippet from "Iridescent" (this is no longer available). A few days later, Mike Shinoda, one of the band's lead vocalists, confirmed that the song will be the fourth single from A Thousand Suns. He also confirmed that a shorter version was made for the film Transformers: Dark of the Moon, which is circulating around the internet. Shinoda said that the collaboration began when Michael Bay, the director of the film series, phoned him about the possibility of the band continuing their run with songs paired with the Transformers films (having chosen "What I've Done" for the first film and having recorded "New Divide" specifically for the second). Shinoda decided to put "Iridescent" in the film due to the fact it was a fan favorite and called it a "natural fit", despite the song not being an "in-your-face" kind of tune.
The film's composer, Steve Jablonsky, who is a longtime fan of the band, agreed with the choice, saying that the song fit well with his score, as well as the film's story.Both Shinoda and Jablonsky agree that the song is an appropriate choice for the film, since the film is described to be more "positive" than the previous films and is consistent with where the band is at (learning from mistakes; going in different directions).
"Iridescent" is a rock ballad about hope in the midst of chaos and sadness. Just like their previous single, "Burning in the Skies", Shinoda sings the verses while lead vocalist Chester Bennington sings the chorus and backup vocals on the verses. On the third chorus of the song, all six band members sing together.
Some LPTVs (behind-the-scenes footage) show the creation and development of "Iridescent", such as the inclusion of gang vocals in the third chorus of the song and the initial discussion about the song
In June, Linkin Park held an artwork contest for "Iridescent". They announced the winner on June 23, 2011.
The official music video was directed by Joe Hahn, the band's turntablist. In an interview with MTV, Mike Shinoda stated: "All I know about the concept is that Joe Hahn sent me an e-mail that said something about 'In the valley of the blind, the one-eyed man is king', or something like that. And the next thing I know, I've got horns growing out of my shoulders, and I've got one blind eye, and I've got a white dog and a snake on a throne made of antlers. I think you'd have to ask Joe what that all means."
In the behind-the-scenes video for "Iridescent", which was released on May 31, 2011, Hahn stated that he wanted to combine the "soulfulness" of Transformers: Dark of the Moon to the soulfulness of what they do, as well as elements of robots tying into human existence.
The music video for "Iridescent" was released on June 3, 2011 on MTV and VH1. The video shows Mike Shinoda as a one-eyed king, with horns sticking out of his shoulders, ruling over the citizens of a post-apocalyptic land. Numerous citizens of the world are wearing ragged clothing, including the other band members. Some scenes also show the band sitting together in a feast, mirroring Leonardo da Vinci's painting "The Last Supper". Numerous scenes and stills from Transformers: Dark of the Moon are inserted to the video. Hahn stated that "the video explores how human existence might be affected by the elements of Transformers robots and the threat of the Decepticons."
On June 29, 2011, the same day Transformers: Dark of the Moon was released in USA and Canada, the band released a 3D version of the music video on YouTube
