Edited this post after tests and experiments showed me what I needed. I also found Curtpalme's tutorial on HCFR that answered most of my quests
I have a service manual for the 40PFL3705D/F7 and I entered the service menu for the with the intent to correct the color cutoffs and drive. The service manual has the info on how to set those in Cutoff\\Drive menu.
However, I also accidentally entered a mode (not in the service manual). The mode had red, green, black, white, a fine striped pattern, gray, a rectangular box etc. Pressing the volume up\\down showed a value for most that could be adjusted. Unfortunately the value only shows AFTER you make an adjustment. The pure colors and white showed "gradation" and a value of 255, black had 0. The striped pattern and gray patterns allowed adjustment of VCOM1 and VCOM2. VCOM1 and 2 displayed with a value of 108 (may have been 108V). Since the initial value is never displayed and the remote may jump 1,2,3 values up from the initial, I don't know their initial values.
So here are my questions:
What are VCOM1 and 2 and what do they adjust? Can I use them to fix gamma?
What are the VCOM1 and 2 values out of the box value (106,107 or 108)?
What is "gradation" anyway? Does that fix gamma? Why can it be adjusted from the service menu, is it just a test pattern?