A couple years ago I gave up on looking for app support and started using "invert colors" (under accessibility settings) so the whole screen is always inverted.

A couple years ago I gave up on looking for app support and started using "invert colors" (under accessibility settings) so the whole screen is always inverted. No special app support required. I only switch when I'm watching a video, and that's my internal reminder that I'm probably not doing something productive.