Opium is a narcotic drug in the Twelve Colonies of Kobol. It is legal on Caprica in the years leading up to the Cylon War. Bars such as the Dive Bar in Caprica City provide smokers and offer at least one variety of opium called "Purple".
Fifty-eight years before the Fall, Sister Clarice Willow is a user of Purple, frequently slipping into opium-induced hazes (CAP: "Rebirth"). One such haze causes her to "drunk-dial" Amanda Graystone, however most of the voice message she leaves is cut off, preventing Willow from exposing her unsavory relationship with Graystone's daughter, Zoe (CAP: "Gravedancing" deleted scene). After they develop a friendship, Willow takes Amanda Graystone to the Dive Bar where the two women smoke Purple together (CAP: "Ghosts in the Machine").