The pages from each book have been colored-in to help provide insight into possible coloring choices and so a low-resolution preview of each of the pages can be provided on the website. The completed renderings do not represent a level of expertise required. While some are renderings may represent a higher skill level, renderings on other pages include really bad coloring and odd color choices. Sometimes, the "artist" made stuff up that was not included in the original page; and you can too!
If you are trying to get to the Amazon site to purchase the book, click on the book title portion of the header instead of the preview portion.