The paper version was announced as "printed in black & white". https://manning.com/books/nim-in-action?a_aid=niminaction&a_bid=78a27e81
But the ebub and PDF version has color and looks nice. There is no reason to buy paper in these days (if the book is not about string theory, quantum mechanics or compiler construction) -- better buy electronic version without discount, maybe one more for a friend, and support bounty source. My opinion.