One of the most important rules in security is awareness. If you study law enforcement, you will learn about Cooper’s Colour Code, which is a simple system for situational awareness. Simply put, white is indicative of a relaxed environment in which one is relaxed, unaware of what’s going on around him. His guard is down and he is vulnerable to attack.
Yellow is when you remain relaxed, but aware of your surroundings. Your response to a threat should be preplanned. Orange represents a state when you have identified something of interest that may or may not be a threat and concentrate on it till you are satisfied it’s not a threat. Red is when the focus of your attention in condition orange does something you find threatening and you shift to condition red. You can choose to defend yourself or run for safety.