How about this ….
What does a stupid pigment shift do for your high ? …. Answer … nothing .
Purple strains exhibit Anthocyanin water soluble pigments just like a berry. And as such have some antioxidant qualities same as those particular fruits. But for adding any psychoactive increases …. No.
Sure you could introduce some stressors like ph fluctuation , cold temps , etc.
But as I said before , Purp strains / reds / grapes and all that are nothing more than picture pretty girls.
You will find most meh smoke and only good for looks.