Alert level

From Red Faction Wiki
The alert icons. From the left: Green, Yellow, Orange and Red

In Red Faction: Guerrilla, the alert level indicates how focused the Earth Defense Force is on killing Alec Mason. The higher the alert level, the more effort the EDF is willing to put into finding and killing Mason.

Green
EDF personnel will not attack you during green alert. To start missions or use Guerrilla Express, the alert level must be green.
A cheat code allows players to disable green alert.
Yellow
During yellow alert, the EDF will attack Mason, but they will not call for reinforcements.
Orange
During orange alert, the EDF will call for backup, and gunships will begin to attack.
Red
During red alert, the EDF will do whatever it takes to stop you.