PocketBook Reader lets you change the background color to whatever you want. You can also change the line spacing/font size/etc, and it’s possible to add fonts as well, if you need something specific. It can be a little convoluted to make it do what you want, though, and there’s not much documentation. (I’m happy enough with it, but YMMV.) Also, no automatic line highlighting that I can find.
PocketBook Reader lets you change the background color to whatever you want. You can also change the line spacing/font size/etc, and it’s possible to add fonts as well, if you need something specific. It can be a little convoluted to make it do what you want, though, and there’s not much documentation. (I’m happy enough with it, but YMMV.) Also, no automatic line highlighting that I can find.