I have a monochrome VGA 12" that I bought at a liquidation store years ago. It was labeled "not working" so I paid like $10 for it, took it home, powered up and it had one line down the middle of screen.
I knew from that symptom to look in the horizontal deflection area around where the yoke plugs in and sure enough, I found a pin that had never been soldered !! This had to have been brand new because no way it ever worked. It has a beautiful gray picture. Of course, it hasn't aged much because I seldom use it except for a quick and easy test display. It's quite small so fits nicely on a test bench.
Ah, i nearly forgot about it, but i also have this monochrome amber VGA CRT - i never think of it as a display since it is that weird kinda display that you build into 3 empty 5.25 drive bays in a tower. It was originally sold as a "file server monitor", i guess back in the days you used a big tower case only for file servers (Aight just kidding here). I really should take a video and some photos of that one since it's a true oddity...
I think these old gas-plasma displays are all orange - starting with the good old Plato terminals and ending with todays Pinball machine displays. Prolly because Neon was the only reasonable gas to use in them and its charismatic orange discharge gives the displays a pretty good brightness and contrast. I guess a mixture of Krypton and Neon could be used for a greenish discharge, but i don't know any gas plasma displays using this.
I'd have called that "orange", but like all the other orange gas plasma displays: If you adjust brightness and look from a certain angle it is nearly a "reddish orange". But same technique as the ones we were talking about.