The story I heard once goes that someone had a supply of tags in a service shop during World War II. They happened to be yellow and thus a tradition was started.
I've heard that too...true? I dunno....
But the civil aviation always looked to what the military did, and copied their methods.
The "tags" are a hold over from the AIR CORPS.
I always thought green would mean good, and red was bad, yellow should mean it needs rework...
Just like a three light traffic signal!...GO, Slow and STOP!
