hi there, im 1 week from harvesting and about 2 weeks ago the leaves on some of my ladies turned a bright yellow on the outside rim ang fade into a purple. is this a lack of something? Im doing it organicly with worm castings and 2 different kinds of bat guano(one high in nitrogen the other potasium)but i have noticed before the leaves seem to turn yellow close to harvest but i have not seen the purple before. anyone that can help i would appreciate it