old post but ive been wondering the same n have not found an answer. i know some turn colors better outside usually from weather or light, but what would it take to make them REALLY turn the colors indoors? like is ther a way to better ur chances?
Cool temps, correct amount of stress and maybe an extra hour of dark to slow the growth as well. Could look into what light spectrums would do what to which strain but im kinda busy. happy googleing.
If you want purple nugs start with a purple strain like lavender(there are plenty other to choose from and can be ordered from seed banks)........cold temps can turn non purple strain purple but mainly the leaves will turn purple not the buds........a true purple strain will have purple calyxes..........
Strain dependent but the Mendo Purp (Grand Daddy Purple) will turn purple indoors...like stated above it helps to drop the temps the last 4 weeks of flowering