Green Box Flashlight with green / red / black filters. It was a leather strap with button holes, attached to the flashlight. NATO Stock #: 6230-12-120-3659. Color filters on Flashlight? What are the purposes of using Color filters for a flashlight? The colors Red, Green, and Blue? 1 - Protect your own night vision 2 - Not reveal your position/presence Red - does the best job of protecting your vision, but is close to infra-red band so an enemy with night-vision devices has a better chance of seeing the "hot-spot". Blue - Not as good at protecting your own night vision, but you can see better to get around. Furthest away from the infra-red part of the spectrum. Green - the human eye is most sensitive to the green range of light. Forests have a lot of foliage that already absorbs all the other colors and only reflects back green light anyway... It should provide the best visibility in a forest using the lowest light intensity possible.