I think you should buy the whole set, Red, Green, and Blue
And then share what you learn…
Here is what a few Googles say about the applications of each color..
https://www.armytek.com/products/accessories/filters/
A Red filter has a larger number of applications. Some animals can't see red light so it's good for nigth hunting and is good for map reading because it doesn't disturb night vision. Flashlights with red filters are also widely used for signage.
A green filter is suitable for hunting and tactical use as a beam of green light can't be seen from aside and doesn't disturb a game.
A blue filter is widely used with various night vision equipment as well as navigation devices. Blue light is also perfect for reading chart and maps.
https://www.amazon.com/dp/B004ANZPCG/?tag=cpf0b6-20
•Red - Preserves Night Vision
•Green - Best Clarity Under Low Light Conditions,
•Blue - Easy to Trace Blood Trail
http://www.survivaledgelights.com/colored-flashlight-filters/
Red Filters
Red light does not detract from your night vision. That is why taillights are red. By using a red filter over your tactical flashlight, you can quickly read a map or get your bearings without destroying your night vision.
It has been one of the most popular choices to add as an optional filter.
Green Filters
Green light has a very narrow band. For that reason, it is often used for night hunting. Animals are not frightened by green light, and it cannot be seen from the side – only straight on. This makes it the ideal filter for your tactical flashlight when stealth is at a premium.
With the human eye being most sensitive to the green range of light this makes it an optimal color to use when traversing through the forest when you are using a low intensity.
Blue Filters
Blue filters are often used when reading maps or other writing because they cast black lines in stark relief against white paper.
One of the additional uses of blue filters is for hunters. Tracking wounded animals at night means picking up a blood trail. The blue light helps the blood stand out against foliage.