I have read all sorts of ranges for this plant, and I can't get a definitive answer. I am not trying to carpet with it, I just want it to maintain its bright green color.

Tank is a 36g bow front. Currently I'm running the aquaticlife T5HO fixture with 24W 6500k and 24W 650nm light I have also received mixed reviews on the 650nm in a separate thread, but based on everything I read despite its low visual appearance the wavelength is perfect for plant growth.
Additionally I have another T5 dual fixture with 2 x 6,700K 18W (sub-par but its on there for extra-light)

So my "watts per gallon" is around 2.3 right now, but I've been told that is very much a general rule and when HO lights are involved sometimes things get different.

My stem plants, grass etc all doing great. HC is starting to dull in color and turn slightly yellow/brownish. It's currently attached to driftwood not in the substrate. I am dosing with flourish excel basically daily.

One thing to note is that I am currently cycling the tank but I was told this would have no effect (the nitrites are through the roof right now). Also the temp is ~84 degrees. I am wondering if this is the problem because the light isn't exactly low. Any thoughts?