Ah... there is a lot of conflict, but genetics make pretty colored hairs with matching caylaxs. Sure there's some in nature, but its bumped up through selective breeding. The afghanies? They ARE genetically pre disposed to turn purple as they mature & the nights chill. Lots of indica dominants have this characteristic. You see it in the leaves & calyx. Even thought they are predisposed to do this, its still an indicator of ripening & maturity & cool nights are the triggers. Won't go into it here on Pappas thread, but a discussion in landraces & their history would answer a lot of questions. I have a friend on another forum that would blow your socks off on this subject. Follow me to my thread & I'll tell you about him.
-- Papapayne, I'm so sorry we sucked up your thread! Its so hard for a ratchet jaw like me to just STFU sometimes! But follow us over to my camper closet grow for the info on this guy. Everything about his grow, ethics & ideas are very interesting! (& he can give a history lesson that will not disappoint)!