If light colours will have specific meaning for a mission, they will be specified in the issued orders. I believe 2RCR exerimented with chem light markings during a series of night dry and live exercises a couple years ago (using IR only?), perhaps someone who was involved can elaborate.
With the amount of night vision equipment available now to line units, the use of chem lights in a lot of areas can be counter-productive.
I do remember the first time 2 RCR used them on a large scale in training. It was the spring of 1986, if I recall correctly. Recce Platoon laid out the assault route to be followed by the battalion for a dismounted night attack on Day Hill. Recce had marked the route with chem lights during daylight, the plan being that the last detachment out, less those picketing the assault position, would break the lights as they retired to the battalion's assembly area before dusk. The next time anyone crested the ridge at Monument Wood was about midnight as the approach march started. Even from the FSCC, I knew something was up from the remarks on my fire control net from the Fire Controllers. Apparently, no one had done an experiment for the range of visibiity of the chem lights, we'd all seen them up close, but not over distance. The route to the attack position, and the assault line were visible for th entire route, like landing guidance markers for E.T. Certain senior officers were not amused.