I saw the original movie on TCM or AMC about two years ago. I still remember one scene where the Spartans explained that they wore red cloaks because they did not show blood and thus the enemy would not know which of them was wounded or not.
I wonder if that scene is the source of the old brown pants joke. Frank Miller saw that movie and loved it so much he made the graphic novel, now of course his novel is a movie. Something for the "not historically accurate" crowd to keep in mind.