I don't understand what the point is with having an e-reader with a colour screen when the screen is so small. Anything I read that would benefit from a colour screen is either a PDF or a comic, and those suffer from tiny letters on a screen under 10 inches.
Or is there a lot of newer books that have images and such that aren't PDF/CBR based?
pdfs don't have a hard-set text size, and cbr/cbz is just a bunch of jpegs in a rar or zip file, respectively. the first one is a non-issue if you reflow and the second one can be zoomed in to. granted, neither is ideal, but it's workable.
personally i've kept it to comics in pocket format.