The royal standard of France was once a plain white flag (to which a fleur-de-lys was later added, and which was replaced by the Tricolor).

Ancient historians from both China and Rome noted the use of white flags to signal surrender. In the former empire, the tradition is believed to have originated with the reign of the Eastern Han dynasty (A.D 25-220), though it may be somewhat older. The Roman writer Cornelius Tacitus mentions a white flag of surrender in his Histories, first published in A.D. 109. His reference concerns the Second Battle of Cremona, fought between the Vitellians and the Vespasians in A.D. 69; at the time, the more common Roman token of surrender was for soldiers to hold their shields above their heads. It is believed that the tradition developed independently in the East and West.

As for the bland color selection, it was likely just a matter of convenience in the ancient world. Artificial colors were still centuries away, so white clothes were always handy—not to mention highly visible against most natural backgrounds. Vexillologists (those who study flags) also opine that plain white provided an obvious contrast to the colorful banners that armies often carried into battle.