r_colorgrading toggler

I am a regular user of Nighthawk potion. As you might know, it is blinding at day time (around until 10pm)

For me the easiest way to disable the effect was console command r_colorgrading 0.

But it also affects other visuals. For example blue tint on low stamina and overall contrast of graphics.

So i decided to add it to hotkey for quick toggle.

Bound to f3 by default, you can change it in mod.cfg

Seems to be working without -devmode launch command