To fade or not let fade-away?

As I look around the forum, I see plants that have been chopped with fully green leaves.. While I thought it was normal for the leaves to began to lose color nearing the end of the plants cycle, going into harvest...am I missing something?? I thought my plant was using up its reserves in the leaves... as I simply water her out...I thought I should be depleting my soil? So what am I missing here? Any help would be appreciated...& thanks to YOU GUYS/GALS..@ RIU, my plants are by far 10 times better.. thanks again to anyone has helped my out in my first year... too many names to name but your all greatly appreciated!!

It is normal for plants to change colors in the final weeks; especially if your plants are feeding from the soil naturally. Bottles nutrients can keep them green far longer than is needed. Usually when a plant matures the fans begin to yellow off but the sugar leaves will stay green as long as there are still nutrients in the soil to pull from. The plant starves/eats itself to preserve the bud.
There is no rule saying you cannot keep a plant green right up to harvest. My soil never depletes; it is too active to stop working. Some of my plants will turn to blues and reds by the time I chop them whereas others remain a healthy green. Sometimes it is due to temps and other times it is a strain characteristic. Other times by week 6-7 the fans are fading to yellow yet the buds continue to develop as normal.
I never "flush" because my grow is mostly water only. When I used cheapo crappy nutrients years ago my weed always had an off taste even when i "flushed" for weeks. I attribute this to my choice of nutrients directly. No amount of flushing can remove what is in the flesh of the plant; everything you add to the soil eventually gets into the plant.
There is no need to feed once the buds are fully developed. Once they are in ripening mode plants need very little if anything to stay alive; so for the final 10 days or so just water them. Not really a flush though just water your plants as normal.

If you cant finish fully green then your plant had stress that yellowed the leaves.

Mainly peeps that cant finish fully green made up the idea the leaves yellow at the end.

Some nutrients are essential for a plant to finish, some canna scientists (finally some did something noteworthy) used organic chem techniques to reverse engineer a bud and found that if you short a plant on boron at the end it isnt good as well as manganese and will slow the finish even stunt it.

Even the flush/fade is more aimed at nitrogen and was more a chlorophyll idea not that plants finish yellow. A pro tip is learn to finish fully green at the right nutrient level and then you can decide what you want rather than those that only have one choice - yellow