I fly a performance light aircraft here in the UK - Vans RV-6. I've equipped it with an Electronic Conspicuity (EC) suite for safety. My first line of defence is a new Mode S transponder with Extended Squitter enabled - this is the bit that performs the ADSB-out function. I feed GPS positional info from a Pilotaware unit which is directly wired into the transponder and has it's own dedicated power supply. A professional avionics engineer was involved in this so no "explosion in Maplins" thank you........
Thus I am visible to all ATC units with seconadry radar, and other aircraft that can receive my ADSB transmission. Using PAW means that I can receive ADSB from other traffic, as an aid to my VFR "see and avoid" principal, and have had numerous encounters where it has proved it's worth as an aid.
Just to correct a bad piece of fake news from the OP, the forthcoming met uploads from Pilotaware are standard Metars with visibility in nautical miles as is usual in the UK.
The colour coding proposed has absolutely nothing to do with military operations - many light aircraft pilots will have no knowledge of RAF procedures anyway.