There's a reagent test colour chart knocking around somewhere, either here at the Nexus or, with absolute certainty, elsewhere on the internet - probably wikipedia. I know for certain there are at least two charts, one with the more usual 'old school' drugs and another with the more recent alphabet soup of RCs.
Colour test reagents are only ever presumptive and may not indicate the presence of some very dangerous substances. The only way to approach certainty of what you have is to send a sample to a drug testing laboratory. Avoid obtaining substances from untrustworthy sources and grow the plants yourself.
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli