(Quoted you here so as not to distract too much from the other app’s topic)
The theming in SD should let you change the background colour, and several of the themes do.
Since e-ink devices that run Android are (although still niche) becoming more commonplace, I’d be happy to look into making the theming support the better. What colours do you feel would be best suit e-ink? Simple greyscale elements on white background?
(I use e-readers, so have some idea of good contrast, etc., but I’d appreciate knowing what you feel would work best)