Feature request: Setting to adjust Darkroom color

[itinerati]

I use Darkroom mode while navigating large container ships at night. It helps me keep my night vision when using applications on my Mac. It's good, but it's still too bright and too red. I'd like to request a feature to set the color manually. Probably the easiest way would be to let the user toggle the Mac color picker and choose from there.

Thanks for the great work on this application!