Revelation chapter 6 prophecies what happens after Jesus opens the first six seals of the scroll. The first 4 seals describe 4 horses of different color: white, red, black, and green (Greek "chloros"). Each horse represents a different kind of catastrophe to the world: territorial expansion (white), war (red), worldwide economic collapse (black), and death (pale green) to a 1/4th of the world. The colors of the flags of the Muslim nations are also white, red, black, and green. I find it difficult to dismiss this as mere coincidence. IMO the first two horsemen are already riding and the 3rd (worldwide economic collapse) could happen without warning at any time.