Here's a couple at harvest and yes the leaves are getting a bit light in color, BUT, that may be because I was playing games with bloom foods or using a flash which makes the leaves look much lighter, witness my avatar. I just don't remember. Most old fan leaves are still pretty green and intact for this indica dom mutt (TrainwreckXSweetTooth) at 11 weeks flowering.
I grow a lot of plants, mostly perennials, thousands of them and one observation I've made is that perennials tend to lose their leaves upon flowering/fruiting. It depends on the variety though. For example, my peach trees will fruit but the leaves remain green until frosts. I have a Mex lime that sheds most of its leaves a couple of times a year. Really weird. It just got thru fruiting big time, is dropping leaves all over the place and is flowering again. I have an avocado variety that drops 95% of its leaves when it blooms and then as it's finishing off that cycle flushes with a robust flush of leaves.
Bottom line? With cannabis it's a cultural thang driven by the grower. The fact is leaves produce bud (not bloom foods) so I strive to keep the leaves green until harvest as they produce food for the buds via photosynthesis. Now, if folks can't see the science in that (and many don't here) they need to find another hobby.
UB