A rainbow flag is a multicolored flag consisting of the colors of the rainbow. The colors used differ, but many of the designs are based on the spectral colors of red, orange, yellow, green, blue, indigo, and violet that compose the visible light spectrum. The actual color attributed as "blue" or "indigo" is cyan.
There are several independent rainbow flags in use today. The pride flag represents LGBT pride (since 1978). The international peace flag is especially popular in Italy (since 1961). The International Co-operative Alliance adopted a rainbow flag in 1925. A similar flag is used in Andean indigenism in Peru and Bolivia to represent the legacy of the Inca Empire (since ca. 1920).
American Revolutionary War writer Thomas Paine proposed that a rainbow flag be used as a maritime flag, to signify neutral ships in time of war.