`insetGrouped` list style causes "smearing" effect on OLED displays in dark mode

[ualch9]

The smearing could be a major visual distraction to dark mode users. Might want to add new setting to change background of list view to a super-dark gray.

For inspiration, Apollo for iOS uses a grayscale value of 5%, #0D0D0D, when the "reduce smearing" setting is turned on.