Surefire’s legacy products the M500 and M900 had separate led navigation lights (I think the options were red or dim white). They were intended for low light navigation with appropriate muzzle discipline like El Cid referenced. The Aviator light also had a color LED option for when some close in work or minimal illumination was necessary without messing up one’s night vision. I have also read that red and green lighting is better for fine detail, but I also believe that’s true mostly at close distances, like reading a map or other “admin” tasks, as opposed to across the room or down the alley distances.

Predator hunters have used green light for years. The theory is that the green light is not as recognizable to many animals (coyotes and pigs?), while again, preserving the hunter’s biological night vision and situational awareness. It’s not better light, in its purest sense, it’s sufficient illumination for the task at hand while offering some ancillary benefits.

For defensive purposes, white light has been king for a while. Reason being, white light is typically brighter, allowing the user to not only make out the subject, but distinguishing features, like facial features, clothing, objects in hand, etc. Predator hunters don’t have to have that level of specificity in target identification, normally; they aren’t looking to distinguish a pig from a pig with a gun it’s hand, or a coyote from a different coyote with a goatee. If they’re after a specific animal, like culling a nuisance predator, white light might be more appropriate.

Back to defensive use. White light illuminates a possible subject better. It allows for better recognition of fine features at a little more distance, objects, etc., and may or may not provide an advantage by blinding the subject or offering a psychological advantage. White light also, in my experience, also provides better depth perception. The downside is that bright white light also degrades your own night vision. I tend to think that in most circumstances that’s an acceptable trade.

One of the truisms of CQB is that the most dangerous room is the one that you’re in. In its most basic sense, you can consider a four walled room with you and the subject in there. There MIGHT be a dude waiting for you outside the spill range of the white light. I acknowledge that, but tactics and other factors have to mitigate that risk. I also extend the concept of the “room” to the cone of light originating at you and extending to and beyond (4th rule) the subject you’re illuminating. There IS someone in that room who you have to deal with first, before the hypotheticals. White light gives you the best illumination, and therefore the most information, so you can make the best decision in that moment.