LG 27GP850P-B questions

[sarunass863]

hello i have had the 27gp850p-b for a year now, my settings were gamer 1 color saturation all 6 colors on 65%, brightness on 100% and nvidia control panels digital vibrance on 70% all were fine until i started digging for better visuals... switched the nvidia control panels colors from default to nvidia full spectrum and noticed colors started looking better but then i read that digital vibrance ruins color so i disabled it but only on 70% or above color saturation in monitor settings the colors look good anything lower is really dull. what settings do you use ? also i found that setting too high color saturation makes the brightness too high and starts to hurts my eyes (to add to that i have used ICC profiles from rtings and official LG site).

my questions:
1:what 6 color saturation % levels should i be using (default 50% looks really washed out dull)
2:does nvidia control panels digital vibrance ruin quality of the image ? (in a way like making 1440p image look more like 1080p or blurring the image)
3:does monitor settings 6 color saturation levels cranked high ruin quality ?
4:what brightness should i be using is 100% too much ?