Your eyes are more sensitive to blue in darker
conditions, relative to the other colors.
The best use for blue light is for use in
water: blue light goes straight through the water without reflecting the
light back. You can see through the water as if it wasn't there.
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.
Most blue lights on the market are useless for
tracking blood trails.
Blue light is the only light that can cut
through fog, but it's a fraction as bright as the light from a