Despite both being cool toned, a blue flashlight is used differently than green flashlights. Green flashlights don't trigger the same kind of fluorescence as a blue flashlight does. Red light is much warmer than the cool tone of a blue flashlight. At first glance, blue flashlights and UV (black light) flashlights seem the most similar. Because UV light is outside the visible spectrum, it looks much dimmer to the eye than a blue flashlight.