Rainbow is the name of at least three bands: 1. A British hard rock/heavy metal band. 2. A K-Pop group (레인보우). 3. A U.S. psychedelic rock band. 1. Rainbow was a British hard rock/heavy metal band formed by Deep Purple founder and former guitarist Ritchie Blackmore in 1975. In addition to Blackmore, the band originally consisted of former Elf lead singer Ronnie James Dio, bassist Craig Gruber, drummer Gary Driscoll, and keyboardist Micky Lee Soule.