The hospital is very limited in it's color scheme, mostly white, brown, and pale green. This gives it the feel of a very clean, orderly, and frankly unexciting place. But these colors also serve to make the hospital the perfect backdrop for more vivid visuals. It's given the feel of an empty canvas onto which anything can be painted. Thus we see the imagined world of Alexandria's is fresh and loud, with highly saturated primary colors. Completely opposite from her hospital surroundings. Even in the darkest moments of the story the imagined world is still bright and colorful.
