The Department of Homeland Security is getting rid of the color-coded threat level system. It was introduced after 9/11, and was supposed to tell you how likely a terrorist attack might be. Except that it never did.
Attacks happened more often when the level was yellow (“significant risk”) than when it was orange (“high risk”). And the one time it was red (“severe risk”), nothing happened. It’s never been blue or green, the two least dangerous levels.