The colors are the Pan-Arab colors, representing the various caliphates and dynasties of Arab history. The red triangle represents the Hashemite dynasty and the blood of martyrs.
History
Adopted by the Palestine Liberation Organization (PLO) in 1964. It is based on the flag of the Arab Revolt used during World War I.
Construction
A 1:2 ratio. A horizontal tricolor of black, white, and green with a red triangle at the hoist.