Yea I know, it looks very pretty , like autumn in the tent
. It hapened to me once and it was weird , that why I think it is deficiency. The leaves are getting golden red and some sort of dark colour , it looks cool, but at the same time it indicates that it is lacking something and is running out of it. That is all .... Perhaps is better to leave it alone, but what if you could keep it going for another 3 weeks it only can get bigger and at day 67 she is not finish.
Usually they recommend 70,80 days cycle, depends on the strain (in perfect conditions,no deficiencys), for most of us it means extra week or two because of the problems we run into.
Good luck brother ...
so I'll wait and cut her, when "leaves will tell" 
