There are MANY documents that Reader fails to impose Dark Mode settings; my most recent example is: (2022) Praxeology volume 1: Frame, on self-actualization for the modern man by Rian Stone. Closely related is how to handle pictures, charts, ... in Dark Mode. The solution will require forethought - sometimes (e.g., graphs), inverting the color palette will work just fine, but pictures would turn into photo negatives, so they shouldn't invert. I doubt one-size fits all dark mode can cover both use cases. You can easily recognize pictures given their wide color palette and smooth transitions vs charts & graphs that typically use only few colors, e.g., one for each series in a comparative time-series graph and vector-based (geometric) pics. Photographs could be tagged at creation time or automatically identified as being unsuitable for color inversion where charts & graphs could get tagged as color inversion-friendly. It's RARELY about how the document prints, much more often it's about how it renders on screen. Please don't conflate those use cases.