Granddaddy Purple strain normally displays its purple coloration about a week or two just before it’s all set to be harvested. There are actually hints and hues of purplish colours over the plants when they start to flower, but ordinarily not over the vegetative phase. GDP showing its purple colour http://purpleskittles22100.dgbloggers.com/15876271/the-ultimate-guide-to-purple-skittles