I have seen apps that lower the brightness, but is there a way to get rid of all light colored backgrounds such as (selectively?) inverting the image colors? For instance, I have an app that only provides black ink on a white background; this emits a lot more light at any brightness level than if I could reverse it to show white ink on a black background while in night mode. Ideally even all light colors would turn to solid black and all dark ones to a gray light enough to see. Some apps provide the ability to control these colors, but others do not.
Is there some in-built way to accomplish this starting with any specific Android version, or some other way to accomplish this? Simply reducing "brightness" is insufficient when the goal is to be able to use the tablet for short periods during the night without disturbing one's partner or even affecting one's own sleep cycle.
Update: Also, it seems the backlight by itself emits a lot of light even on a black screen, and the filter approach does not seem to affect this at all.