Bioluminescence in the shadows

Some changelings of the 2061 passing of Haley's Comet exhibit the condition of bioluminescence. For the most part it is seen as a disadvantage as they stand out in low light conditions and darkness. Yet, people do prevail over adversity, for, some have learned to control their bioluminescence to a degree and communicate with it. 
Using color patterns and a series of flashes both bright and dim a simple language reminiscent of Morse Code was created. Not an exact copy per say but a working language in the progress of further development.
The language of light as some call it has been seen being used in at least four situations.
Predation; some of the light code has been used to signal others within the group as to when a hostile person or group is nearby. Then a decision is made as to whether or not engage or retreat.
Camouflage; a few individuals have been observed using their ability to hide and conceal themselves by standing near other light sources. In effect becoming part of a neon sign. Though this can be dangerous is there is an amp in the voltage.
Reproduction; color patterns and intensity, tone and hue of the lights can be a signal to one's receptiveness to or aversion to a sexual encounter. Softer subtle tones and hues being positive. Where as bright and glaring colors are a warning.
Empathic responses; light patterns can indicate if there is an emotional response to music, art, one's spoken word, a religious experience or sporting event. The intensity and dimness of the light color determines enjoyment or displeasure.
There is on going research both at the corporate and government level. In the shadows there is work to emulate a wire control process that mimics the biological process. How much money or power to be gained by a breakthrough is yet to be determined.