Flem, I think you misrememberize a bit. We NEVER asked ground to pop a specific color. If you asked for red, there'd quickly be at least three sources of red smoke - all but one from Charlie.
We told them to pop smoke, and after smoke appeared, THEN ask what they'd popped. If the good guys said grape and you saw one purple and one yellow, you smiled because the VC just marked their own position.
Rocky we worked the an lao area for months having had smoke issues with the ground..Charles had bagged enough to have ample supplies on hand, we lost two aircraft just before I arrived that were suckered in because of color alone..that's why we were asking.. Was always up to our right seat to make the call while inbound as we aborted several times before proper measures were taken..Night ops with flares brighter than the sun was the issue with discerning colors..
