Where is the guy that says pick some bud off your plant and smoke it?
Go by flowering times suggested from sign of first white pistils(not 12/12 switch) and get a x30-100 scope for 10-15 bucks and look for 5-10% clear, 5-10% amber and the rest cloudy for trichomes. Also most of the time more then half the hairs should be receding back toward or into bud. Hair color means little to nothing.