A new two-tiered system of terror alerting replacing the five-color approach will provide the public with more details about "specific, credible" threats, Homeland Security Director Janet Napolitano has said.
The system, which was unveiled by Napolitano on Wednesday, will list threats as "elevated" or "imminent" rather than using colors green (low threat), blue (guarded), yellow (elevated), orange (high), and red (severe), reports Fox News.