The best and only thing to do is just let nature take its course. Its cool to add nutes but I use miracle gro bloom booster every other week until 2weeks prior to harvest. You can eff up all your hard work with one paranoid action. So relax if its getting the proper sunlight then your there...
That is true about the purpling. last years harvest handled the frost quite well. Every leaf and hairs turned purple. This years offspring surprisingly turned pink with a slight red-rose tint but the leaves are true green,although the stems are deep purple...