There is a new bookstore in Seattle, Washington where the books are shelved not by topic or alphabetically, but by mood, and I'm all for it.
From The Seattle Times:
Oh Hello Again owner Kari Ferguson admits that in the two months the shop has been open, more than a few customers expressed confusion on entering the store.
"It's really an interactive experience," Ferguson says. "I want a person to come in and look around and say, 'What do I need right now? What kind of book would help me in my life based on what I'm going through, or how I'm feeling?'"
The philosophy for Oh Hello Again's unique categorization was inspired, appropriately enough, by a pair of books. Ferguson was so enthralled by the thesis of Ella Berthoud and Susan Elderkin's "The Novel Cure" and "The Story Cure" that she decided to build a whole shop around their concept of "bibliotherapy," which posits that reading the right novel at the right time can help to console and guide people through moments of great emotional turbulence.
Categorizing books by emotions is more useful and makes way more sense than organizing books by color — which should be considered a crime in my opinion.