Add a splash of color to the walls.
Or be daring and stand out with an usual bold color choice.
Another option is to Introduce color through materials, look how the wooden shelve is highlighted.
Carpet and furniture are another option, it is up to you.
Big bold pieces of Artwork are famous for packing quite a punch.
To add interest and personality be creative with the Shapes of your bookshelves.
Instead of a square library what about a circular Shape library?
Texture is also another great option to add depth to the area.
Patterns are a great interesting way to utilize your space and add a little creativity.
The desolate effect with a glimmer of hope by the use of light and color.
Unique Lighting, choose a shape that really captures the space (height & width).
A well positioned Window and seat.
Alcoves are perfect for creating intimacy and adding character.
Be playful and add a comfortable fashionably Swing.