Color combination first used in the flag of the 1916 Arab Revolt
The pan-Arab colors are black, white, green and red. Individually, each of the four pan-Arab colors were intended to represent a certain aspect of the Arab people and their history.[1]
^Abū Khaldūn Sati' al-Husri, The days of Maysalūn: A Page from the Modern History of the Arabs, Sidney Glauser Trans. (Washington D.C.: Middle East Institute, 1966), 46.