A signaling light source facilitates locating personnel under adverse conditions such as in a smoky environment and resists damage from exposure to a harsh user environment A lighting unit includes at least one, and preferably two, of the signaling light sources also includes at least one personnel identifying red-green-blue (“RGB”) light emitting diode (“LED”) Disclosed methods for operating the signaling light source include energizing operation of a LED light source by supplying a sequence of electrical current pulses which repeat at a rate which causes emitted light to pulse visually, supplying electrical current to a pair of LEDs alternatively connected either in series or in parallel depending upon battery operating condition, and monitoring smoke density in environment around the signaling light source and modulating the intensity of emitted light responsive to smoke density.