The Department of Homeland Security is recommending that the Homeland Security Threat Advisory System -- known as the "color code" -- be scrapped in favor of warnings that would be more specific, according to senior administration officials. The final decision is not expected for several weeks and is currently undergoing an interagency review and consultation with the White House.
In July, 2009, Homeland Secretary Janet Napolitano ordered a 60-day review of the system used to inform the public of the terror threat environment to see if it needed to be altered. The task force appointed by Napolitano was split on whether to keep the current advisory system in place. 
The system, initially set up in 2002, has been adjusted 16 times. It spans the spectrum of colors from green -- or low -- risk of terrorist attack, to red -- or severe -- risk, has never gone below yellow -- or elevated -- risk. Since 2004, the system has been raised to identify specific sectors which were under heightened alert.  
Other countries such as the U.K. and France currently use threat level systems to inform the public about the risk of an attack. In the U.K., the threat level is reviewed by the Security Service MI-5 and the Joint Terrorism Analysis Center.
The U.K. threat level system does not rely on colors but spans five levels from low -- meaning an attack is unlikely -- to critical -- indicating an attack is expected imminently. Currently the U.K. system is set at severe -- meaning that a terrorist attack is highly likely.