Indigo Algorithm -Ai no Denshi Kisuuhou- (Indigo Algorithm－藍の電思基数法－), also known as Quantum Mechanics Rainbow II: Indigo Algorithm, is the seventh (sixth of entirely new music) solo album by artist Daisuke Asakura.

It is the second in a series of seven albums released by Asakura in 2004, called Quantum Mechanics Rainbow.

Each album revolves around a different color of the rainbow and a different term relating to Quantum Mechanics.

The album also contains a re-arrangement of a song originally performed by another, now defunct, band that Daisuke Asakura had produced in the past, The Seeker.

It also contains guest vocals by Takatoshi Shindo (Track 5).