I don't see a significance of color in gun handling, ordinarily.
The 4 rules are what I'm thinking about, color has no meaning.
In aviation, it's fairly obvious. All sorts of things are red/green light based. If a radio goes out and you have to use light signals to approach and land in controlled air space, they are white, red and green.
Guns, I don't care what color you are, I don't point at you unless I want to destroy you.
Not being a jerk, just don't understand the significance.
Still happily answering to the call-sign Peetza.
You do not HAVE a soul. You ARE a soul. You HAVE a body.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.