Rigel Systems Military Infralite Switchable 2-Green/2-Infrared LED Flashlight with Batteries

For use with Military Night Vision Goggles. Switchable between 2 Green and 2 Infra-Red LEDs. The intensity is fully adjustable with Thumbwheel Brightness Control

Use of blue-green is to protect night vision goggles, not unaided night vision! Most red filtered incandescent bulbs emit red and a lot of infra-red and therefore are easily visible in night vision goggles and would overload night vision goggles in the cockpit.

Night vision goggles are not very sensitive in the blue-green part of the spectrum because they use blue-green cutoff filters. That's why blue-green is used in the cockpit.

The military has split the spectrum giving blue-green to the unaided vision and yellow through infra-red to night vision goggles. MIL-STD 1472 makes another point, adjustability, one should be able to adjust the brightness to match the need.

Regardless of color, if its bright enough to dazzle your eyes, it will affect your night vision, hence adjustability as per MIL-STD 1472. So for most of us, the answer is red and adjustable brightness for preserving night vision. The Infralite allows for full adjustability, as well as switchability to Green as well.