Of the 22 members of the Arab League, 10 use the green, white, black and red. Of the other 12 countries, most rely on one of the four colours, usually red or green. AFP
Of the 22 members of the Arab League, 10 use the green, white, black and red. Of the other 12 countries, most rely on one of the four colours, usually red or green. AFP

Why are so many Arab flags red, green, black and white?