Do flashlights (torches) with multi-color capabilities (white, red, blue and green) have any outdoor applications for usage in the forest or while hiking at night?

I have several flashlight that have multi-color capabilities and would like to know how these various colors of light may be used in the great outdoors?

This question is similar to two other questions that can be found on this site, yet are somewhat different:

What are the pros and cons of using a red colored light source for hiking at night?

My head torch/lamp has a red mode, why?

Could someone explain how these four colored lights could be useful to us in our adventures (hiking, hunting and so on) in the wild?

  • What other colors did you have available with your other headtorches? I've only remember seeing red filters. I've seen some kids torches with other filters but I assumed it was for kids to have fun. I don't think there is any application for blue or green.
    – Desorder
    Commented Nov 25, 2016 at 2:01
  • @Desorder I have all four colors, but on two different flashlights. One has white, red and green and the other has white, red and blue.
    – Ken Graham
    Commented Nov 25, 2016 at 2:59
  • There must be some use because I just bought a new headlamp--and I find it has not only white and red (red light doesn't harm your night vision and thus is a common feature) but also green and blue. I have no idea why you would use the other colors, though. Commented Aug 13, 2019 at 4:06

4 Answers 4


Just found this and thought it rather interesting and adds just a little something more to the already great answers posted.

The following is from the Flashlight University: LED Colors and Uses.

White: Great for all around, every day illumination.

Red (630 nm): Red LEDs are do not appear as bright to the human eye as white LEDs. If your eyes are night vision adjusted, it’s a good idea to use a red LED to navigate your way in the dark so you don’t ruin your night vision. Red light is also great for camping if you do not want to wake your neighbors with a bright white light. Red light is the universal signal for attention, so it is a great thing to have in emergencies for signaling and safety.

Green (525 nm): Green LEDs are useful outdoors. Many hunters claim that the green light attracts deer and other wild game, and the green light will not scare away fish, deer, and other game like a bright white light will. The green LEDs also have a longer run time than many other colored LEDs.

NVG – Night Vision Green (495 nm): NVG LEDs, along with red LEDs, are useful for preserving night vision. NVG colored LEDs are useful for military pilots as well, who have special equipment that is designed to work with NVG lights.

Blue (470 nm): Blue LEDs are useful for pilots and other personnel who need to read maps at night. Other colored LEDs (such as red LEDs) will not work for map reading because it will wash out red lines. Blue LEDs are also used by police and crime scene investigators because it will make blood and bodily fluids visible that are usually invisible to the naked eye. Blue light is the only light that can cut through fog, which is why it is widely used for fog headlights.

It should be noted that most animals cannot see true spectrum green and blue can be used for tracking wounded animals.

The following is from Voidhawk Flashlights: The best 3 color RGB Tactical Flashlight available today!

Red: Coming in at 630 nanometers the Voidhawk RGB Tactical Flashlight uses the perfect Red wavelength for tactical applications such as map reading, hunting, or any nighttime activity where you want to save your night vision.

Green: Registering at 535 nanometers the Voidhawk RGB Tactical Flashlight uses the perfect Green wavelength for the human eye. Our eyes are most sensitive to green light which makes it perfect for navigating the dark. Green light gives you a high illumination value without causing you to lose your night vision. Most animals cannot see true spectrum green light very well so it does an excellent job of lighting up a field without disturbing the game.

Blue: Using a royal blue 465 nanometers the Voidhawk RGB Tactical Flashlight uses the perfect blue light wavelength for tracking blood trails of wounded prey without sacrificing your night vision. Blue light is also excellent for fishing at night as it shines straight through the water without producing any glare, it’s as if the water isn’t even there!

Black light (blue) I find great when in a tent setup with others and you want to find something without a bright light to possibly wake up someone else.

  • First quote says red LED cannot be used for map reading, yet the second claims its perfect for map reading.
    – user5330
    Commented Nov 28, 2016 at 20:36
  • 1
    @mattnz Red ink is hard to see with red light LEDs. So If a map does not contain any red ink, a red LED light would normally work well.
    – Ken Graham
    Commented Nov 28, 2016 at 23:36
  • This may be of interest to some: Why do green lasers appear brighter and stronger than red and blue lasers?
    – Ken Graham
    Commented Dec 16, 2016 at 13:36

I know that some animals find hard to see red and they can't differentiate between red and green very well so I'd assume green and red have the same application (used in dark places) with red being a better option.

Ultraviolet light is used for forensic applications but it's a specific blue light not just a light that is blue so I'd also assume that the blue light in your torch is to mock that.

  • 2
    Ultraviolet is very much not a blue light. Some UV lights leak blue, or cause things to fluoresce in blue, but UV is explicitly invisible to us, hence the name. Blue lights in torches have nothing to do with ultraviolet.
    – Rory Alsop
    Commented Nov 25, 2016 at 12:08
  • 1
    "not just a light that is blue" I guess he meant that the Ultraviolet mode also displays blue light so that the person using it sees where he is aiming at with the light. In other words, he does not just display a specific ultraviolet wavelength, but a range of wavelength that also conatains blue for the sake of ergonomics.
    – Vulpo
    Commented Nov 25, 2016 at 14:23
  • Yeah. As Vulpo said. Even because Ultraviolet will actually present things violet, a purple fish color. But it can also appear as blue ish.
    – Desorder
    Commented Nov 27, 2016 at 0:25

If you find yourself hiking along a road at night, especially in a group, a red light towards oncoming traffic may be a good idea. There isn't always a verge to step onto when you notice a car approaching. And some roads can be narrow enough that there's no real correct side and the locals still drive very fast


Red has been covered already, and it really is the most practical colour to have with you at night, as it is the only one that doesn't impact your night vision significantly.

The others, though, are useful for all sorts of signaling or navigation purposes. It can be easier to signal a red or green rather than send Morse code for stop or go, for example. Or you could give navigation instructions to head for the red light then turn towards the blue light.

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