I don't know where the federal government got the idea of a code for the awareness level or whatever it is but it probably wasn't from Jeff Cooper. However, I think it's largely useless to ordinary citizens because they didn't come with any instructions on exactly what you're supposed to do or behave.
By the way, the blue in Blue Train is, well, just the color of a train.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.