One source for Cooper's Color Code can be found here.

While trying to describe an event last year, I was referencing Jeff Cooper's Combat Mindset, and discovered I needed a category that didn't exist!

Therefore, I propose the following adaptation. Call it what you will. I lay no claim to it, but from now on, it's what I'll use:

Blue - Unaware and unprepared. If attacked in Condition Blue, the only thing that may save you is the inadequacy or ineptitude of your attacker. If your attacker is competant, you're likely to wind up being listed as "code blue."

Green - Relaxed alert. No specific threat situation. Your mindset is that "today could be the day I may have to defend myself." You are simply aware that the world is a potentially unfriendly place and that you are prepared to defend yourself, if necessary. You use your eyes and ears, and realize that "I may have to SHOOT today." You don't have to be armed in this state, although it's a good idea to always be ready to defend yourself. Green is reserved for those situations which statistically pose a minimal immediate threat from bad guys, ranging from when you're behind locked, reinforced doors and barred windows, to low-threat situations such as daytime excursions into minimal-threat areas.

One can keep up Condition Green 24/7.

Yellow - Heightened alert. There is still not specific threat situation, but you're now in situations and territories which have a greater probability for aggression. This includes being in unfamiliar surroundings or among people you don't know. You can remain in Yellow for significant periods, as long as you are able to "Watch your six." In Yellow, you are "taking in" surrounding information in a relaxed but alert manner, like a continuous 360 degree radar sweep. If possible, you should either be armed, or you should attempt to move to Condition Green. As Cooper put it, "I might have to shoot."

Orange - Specific alert. Something is not quite right and has gotten your attention. Your radar has picked up a specific alert. You shift your primary focus to determine if there is a threat (but you do not drop your six). Your mindset shifts to "I may have to shoot THAT PERSON today," focusing on the specific target which has caused the escalation in alert status. In Condition Orange, you set a mental trigger: "If that person does 'x', I will need to stop them." Your pistol usually remains holstered in this state. Staying in Orange can be a bit of a mental strain, but you can stay in it for as long as you need to. If the threat proves to be nothing, you shift back to Condition Yellow.
Red - Condition Red is fight. Your mental trigger (established back in Condition Orange) has been tripped. If "X" happens I will shoot that person.

Red - Condition Red is fight. Your mental trigger (established back in Condition Orange) has been tripped. If "X" happens I will shoot that person.