The use of colors for identification purposes goes back deep into history. Alexander the Great is credited with the first use of color to identify different blocs.
As the successful leader of what was then the largest army ever assembled, Al knew that coordination of troop movement was secondary only to logistics, i.e., keeping the troops fed. He repeatedly came close to defeat because his left wing moved at the wrong time or his right wing failed to move at all.
His scientists solved the problem, inventing chemicals that changed color after a certain time of exposure to the air. Alexander dipped strips of cloth in these various chemicals and passed them out before battle to his troops to wear around their heads. Then, for example, when the green bands changed to orange after three hours, those troops knew to advance. Und so weiter.
And there you have the origin of Alexander's Rag Timebands.
