How are the different colored lenses on military flashlights used?

[obisean68]

I'm a little old school but it used to be: red was used at night to reduce visibility by the enemy and preserved your night vision, and blue was used by medics - it was similar to red but blood shows up black in blue light allowing them to find bleeding. The other colors I never used so can't help you there.

[gcrookston]

As Obi stated, Red is to preserve night vision, Blue is to highlight blood. Other 'old school' uses are: amber to cut through smoke/fog, green for low light conditions.