However, I think the kind of media that would benefit from the original page layout would also need a higher resolution, and perhaps colour.

Indeed. Resolution will probably need to be higher in that regard. For books (not comics or art books), color should not be that important.

That being said, the issue of (not) owning and (not) controlling our ebooks is the reason why I stopped reading & purchasing them a few years ago (despite being heavy into those since the early 00s). So, I’m very much interested in that project :)