The Bookshelf Colour Wheel

YA author Victoria Schwab started a really cool Tumblr. She's asked for pictures of bookshelves. When I heard about this, I had to investigate (I've always been fascinated by bookshelves). Then I sent here my shelves:

The books are arranged by colour in part because when I go to retrieve a book from the shelf, I always remember its colour, and in part because I saw these shelves: