>>5548765 (PB)
>>5549115 (PB)
Using Colored Smoke Helps Avoid False Flags
Historical Uses
Colored smoke grenades were first used by American forces during the Vietnam War. They were used to prevent the Viet Cong from employing a tactic known as a false flag maneuver. The Viet Cong would attempt to draw enemy air forces into an ambush by popping standard smoke grenades, or "false flags." By using colored grenades, American troops could provide air forces with a color specific target and help them to avoid enemy ambushes.
Benefits
One major benefit of having several smoke colors available is that it makes it possible for ground and air troops to coordinate multiple operations at the same time. All the ground troops have to do is pop two different smoke colors and make sure their air support knows what each color signifies. For example, they might pop green smoke to indicate there are wounded on the ground and red smoke to mark an enemy target.
https://ourpastimes.com/do-colors-smoke-grenade-mean-6664060.html