It's normal for new leaves to be lighter than the rest when they are growing in, especally when they are growing in at a rapid rate. The bottom leaves do not look excessively dark green at all. Leaves sticking straight up is known as "praying" and is a sign of supreme health and happiness in the plant. Also, all your stems, branches and even stalk are still perfectly bright green without even the slightest hint of lignification (turning brown and forming bark). Your plant looks amazingly healthy and happy, dude. Great job.
The only problem I see is that you should have topped it, trained it or supercropped it, or started flowering earlier, because those lower branches are never going to get the light they need. You may want to add some floro tubes on the side for side lighting, or do some pruning of the lower branches as they will only be "suckers" and suck energy from the plant without ever really producing much of anything.
Oh one other thing, the leaf tips look like they are curling down a bit, known as "rams horn" which may indicate there's a slight pH problem, but it doesn't look too bad at all. Actually just read that dark green leaves and downward curling tips is a sign of Nitrogen overdose. So if you do think the fan leaves are too dark green (kinda hard to guage from a pic), that may be your problem. Have you switched to bloom ferts or started flowering 12/12 yet?
Dude (or Dudette)...remove the blue plastic protection from your reflector unless you like the smell of burnt plastic and reduced reflectivity.
Good call