@ Scroger - Thanks Broooo! I like your moves...
just personal taste but to me the only reason for anyone to force their bud to turn purple is usually because they are sellers trying to make an extra buck off a strain that isnt purple by genetics..
trichs become so much more brittle when forcing a plant to turn purple with cold temps, this tends to diminish the quality of the strain by a pretty big margin. im just very picky i like to get the most out of every gram i grow, for instance i dont ever use my buds for kief, i used to but i noticed how much of a difference it made without scrapping all the trichs off.
just me but i would never do that, the only time i grow purple is when im able to get a strain with those genetics.
Run that A/C over night late in flower and get some nice colors from em!