Indigo: Women of Song is the nineteenth studio album by British-Australian singer Olivia Newton-John. It was first released by Festival Mushroom Records on 17 October 2004 in Australia. An album of cover versions of songs previously recorded by female singers, it was entirely produced by Phil Ramone. Indigo: Women of Song peaked at number 15 on the Australian Albums Chart and was eventually certified Gold by the Australian Recording Industry Association (ARIA).[1] In the United States, the album was issued under the title Portraits – A Tribute to Great Women of Song, featuring different artwork.[2] The album was eventually released in Japan, 2006 under the Universal Music label.
AllMusic editor Jon O'Brien rated the album two and a half stars out of five, writing that "Newton-John's light and airy vocals are the perfect foil for the swooning lounge-pop" of the Burt Bacharach/David, Stephen Sondheim and Astrud Gilberto renditions on Indigo, but "her clean-cut sweetly sung tones lack the emotion to pull off" the rest of the material".[2]