Turning border/background color on/off

Is it possible to choose when the border is and isn’t displayed?
Is it possible to change the background color mid-book?

This question is similar to this one, and for similar motivation. I would like to remove borders from introductions (already possible) and also change the color for introductions (I don’t know how to do). I’d also like to be able to do something similar after the end of a book.