#1774 Allow custom bg color with invert color in dark mode option

[Shuyu Xie]

Now users don't have a choice of the background color with "invert color in dark mode" option toggled on. It's preconfigured to be 45/255. It would nice to allow users to change this through the preference menu. e.g. Personally i would like a darker bg.

I may be mistaken, but those lines in NSGraphics_SKExtensions.m are setting the bg color.

if (SKHasDarkAppearance() && [sud boolForKey:SKInvertColorsInDarkModeKey]) { // map the white page background to 45/255, or 30/255 with high contrast CGFloat f = [[NSWorkspace sharedWorkspace] accessibilityDisplayShouldIncreaseContrast] ? 1.9338 : 1.9338;

[Christiaan Hofman]

We cannot keep on micor managing all things, even through hidden preferences.