Rainbow Syndrome is the second studio album and first major Korean release by South Korean girl group Rainbow. The album was split into two parts, with the first being released on February 13, 2013, containing six songs. "Tell Me Tell Me" was used to promote the release. The second installment was released on June 4, 2013 containing seven songs. "Sunshine" was used to promote the second part.

Rainbow (Korean: 레인보우) was a South Korean girl group formed in 2009 by DSP Media. The group is composed of seven members: Woori, Seungah, Jaekyung, Noeul, Yoonhye, Jisook and Hyunyoung. They released their debut EP Gossip Girl on November 12, 2009, and since released two studio albums and five extended plays, In October 2016, DSP Media announced that Rainbow would disband after seven years because their contracts expired. In November 2019, the group was re-formed for their tenth anniversary.