All of those colors were always there, but they are far more powerful and become a focal point when they are presented this way.
I found these images of people who tried this concept themselves and I think it is brilliant! It has been a theme running through blogs and flicker for some time now.
I even tried to get a client of mine to allow me to color code her 3 massive bookshelves last Spring. She is a former elementary school teacher and tutors children. She has the most amazing children's book collection and I thought it would look charming by color. We organized by genre instead.
So I say Dewey who? Let's get to organizing our bookshelves and add a bit of color to our dreary, snowy February days.
All images borrowed from Google image. I will give them back I promise.