The toga praetexta looked, at a distance, like the plain white toga virilis worn by every adult Roman male citizen, except for a band of purple or crimson dye running along its border. That border marked two very different kinds of Roman standing at once. Curule magistrates, the highest ranking officials entitled to the ivory folding chair, wore it while carrying out public religious duties, as did major priesthoods including the pontifices and the flamines, the specialized priests each attached to a particular god's cult. At the same time, ordinary freeborn boys, and by some accounts freeborn girls as well, wore the same bordered toga as everyday dress from a young age until a boy formally exchanged it for the plain toga virilis at his coming of age ceremony.
Roman writers treated the purple border as more than decoration. It was widely understood to carry an apotropaic function, warding off harm from those who wore it, which fits the pattern joining magistrates performing sacrifice, a moment of ritual exposure and responsibility, with children, who occupied a similarly vulnerable and not yet fully formed position in Roman social and religious thought. Wearing the same marked border linked the highest religious offices in the state to the most ordinary members of it, its youngest.