Quote Originally Posted by stinkyattic
Did you all know that the purple color is actually a plant pigment like chlorophyll (green). Now, a healthy plant will have plenty of chlorophyll in its palisade cells to carry on photosynthesis. A plant that can turn purple in the cold ALWAYS has that purple pigment (I forgot the name of it, sorry) present, but you can't see it because of the green. As the cold weather causes chlorophyll to die and be degraded, the purple shows. This is the same reason maple leaves turn brilliant red in the fall. But-and this is important- they are about to be shed, and the tree no longer plans to use them that year.
That's why Smoky M is right about waiting until late flower to try and cold-stress your plants into showing purple. Any earlier, and you could harm their ability to make sugars.
Yes I did, I thought that was a little bit to indepth for him as all he wants is to smoke purple buds. Good post, btw, the pigment is called anthocyanin for the purple traits. And carotenoid for the red, orange and brown colors in cannabis.