The green plus red is blue boggles my mind.

Still,

I wouldn't call myself a colour spectrum expert, but I'll give it a try:
The NVGs are most sensitive to light at the low frequency/ long
wavelength end of the visual spectrum, i.e. the red end of the spectrum
(and unlike the human eye even is sensitive to somewhat lower
frequencies in the IR range).
Green is associated with higher frequencies/smaller wavelengths than
red. A red light of a certain intensity produces a far stronger response
in the NVG than a green light of similar intensity would, since green
lies further away from the wavelength range to which the NVGs are most
susceptible. Pretty straightforward.
As for the blue, this is associated with even higher frequencies/smaller
wavelengths than the green, so it should be even less visible, which
gives no explanation whatsoever for why green would work better than
blue, unless with blue the worry would be that you wouldn't bee able to
see that at all, while wearing your NVGs.

Wow, this thread has gotten good, imagine that I'm actually learning here.
Unfortunately, I obviously misunderstood the NVG experts words, I thought he
said blue light was closer to the red spectrum than green, but if you're
correct (as well as another poster who posted the exact frequencies for each
color...impressive), I must have misunderstood. Anyway, he was correct, my blue
indiglo watch washed out my NVG's, if only slightly, while the green light of
similar intensity did not.


BUFDRVR

"Stay on the bomb run boys, I'm gonna get those bomb doors open if it harelips
everyone on Bear Creek"