There is no green Ne-2. You can put a filter on a NE-2
and
get a nice red or yellow but not green.
Well, you are technically correct, as "NE-2" was originally a standard
- the little orange glowing tube we all know and love, but there were
some makers that did make a green version. The inside of the glass
bulb was frosted with a green phosphor.
--
Will