A Homeland Security task force will soon review and possibly change the system of color-coded terrorism alerts implemented in the U.S. after the 9/11 attacks. For an Op-Art exercise in Sunday’s New York Times, four graphic designers were asked to develop a new, better system of alerts. Paula Scher created a two-letter system that uses C to stand for Caution and A for Alert. (The A gets an extra slash across its form for added emphasis.) Kurt Andersen provides online audio commentary and judges Scher’s submission to be the most effective because it acknowledges there are really only two states of warning when it comes to terrorism: Caution (“We will always need to be cautious,” says Scher) and full-on Alert.