T&L Publications

Cannot find them on the market. Do you know of a source ?
The ones I see now are red Ne-2 type under a green lens. One uses a powder behind the glass :

----> https://www.aliexpress.com/item/20pcs-G ... autifyAB=0

I remember having true bright green emitting ones a long time ago. The tiny rods inside were white (phosphor?), I think.

Maybe krypton gas bulbs?
https://en.wikipedia.org/wiki/Gas-discharge_lamp

probably a mixture of neon and other gasses

From: https://en.wikipedia.org/wiki/Neon_lamp#Color
A mixture of 95% neon, 2.5% krypton, and 2.5% argon can be used for a green glow,[29] but nevertheless "green neon" lamps are more commonly phosphor-based.

Plenty on Alibaba if you want 10k or more, if you ask around, you might find a supplier with some sample quantities. For most applications they are obsolete for LEDs. you may have to scour the surplus suppliers.

i have a few of them green neon lamps, they actually have argon in them, and the green light comes from the white coating, i actually had a purple one once,,