Firstly, the color really depends on what kind of activity you are engaged in. Kelvin Temperature is the measurement of the color of light, specifically the tints, which are measured in Kelvins. The lower end of the spectrum, from 2,600K to 3,500K, generally give off what is called a “warm white” coloring.
Between 3,500K and 500K offers a “neutral white” coloring. The higher range of 5,000K and upward will give off a “cool white” color that usually has a blue tint to it. These are the most popular due to the efficient light production they offer.
You will also need to consider what kind of bub you want. Incandescent bulbs contain a wire filament that is heated to high temperatures by electricity to illuminate it. Some higher-powered incandescent flashlights use halogen lamps, whereby halogen heightens the power of the bulb. Despite these being replaceable bulbs, they have a short life expectancy; maybe just a few hours.
This makes them less reliable than LED bulbs for a tactical flashlight because they are also more fragile than LED light bulbs. If you drop your flashlight from a height onto a hard surface, the filament might break or come loose, rendering your flashlight useless. The best color you will get out of an incandescent light bulb is around the 2,500K mark.
Flashlight LED bulbs have a longer lifespan and electrical efficiency than most other bulbs, such as incandescent bulbs. They can produce over 100 Lumens for every watt, as opposed to the 8 to 10 Lumens produced by an incandescent bulb. They have a significantly longer battery life than incandescent light bulbs, using about 10% of the energy of an incandescent.
They will produce a range of colors, from a “warm white”, about 3,800K to 4,000K, to a “cool white”, about 5,500K to 6,500K. This makes them the ideal choice of light bulb for a tactical flashlight; you will want a range of colors at your disposal, as well as not wanting your tactical flashlight to cut out when you need it most, such as in a high intensity situation. Combined with a reliable battery, or a fully charged one, you’ll be safe with an LED bulb in your tactical flashlight.
Light Pattern Spread
You should also consider the light pattern spread that you’re going to get from your bulb. Consider the setting in which you will need it. A burning building will have significantly different needs to a big open forest. Or climbing a rock face compared to a dark alleyway.
Most tactical flashlight brands come in to varieties when considering light pattern spreads: flood and throw. You’ll need to make a compromise on these. A flood will spread light upon a wider space, but it won’t reach terribly far. On the other hand, a throw will reach far but in a concentrated and thinner line of space. You’ll get a long and defined beam, but your overall brightness won’t be great. Different flashlights and lights are made to lean more to one side than the other.
It comes down to the design of the reflector and the LED being used. Generally speaking, flashlights that are more floody are best suited for close and isolated inspections of objects. Flashlights that are more throwy are better for closer up inspections of things, or for lighting up a greater area. Before you make the decision, you’ll need to consider the activity you’re undertaking and think about when and why you will need your flashlight.