just some remarks after some self-builded multi-color screens:
let's talk in RGB:
the VFD color (cyan) seems to send:
Red: just a little bit
Green: near from max
Blue: max

So, the best screens (or best colors filters) will be, in order:
cyan
blue
green
the worse will be red (nice -I have one- but poor in luminance)
So if you choose an other color, try to get one with a lot of blue or a lot of green...
for example: yellow (R+G).
It works, but it's more green than yellow (the red part is very small compared to the green one).
magenta (pink) would be nice (R+B), never tried...
If it could help...

__________________________

David Clesse
Belgium/Luxembourg
Mk2-36g(full)-red-tuner-stick