Adding other functional articles such as shelves can help in creating that illusion of design and decoration that your boring walls need. Carefully place each book in the shelves in a certain pattern, so that the eye would not be able to take much notice of the wall and instead focus on the design of the shelf, creating an illusion that the shelf itself blends with the wall as one general theme or design.
Finally, avert the eye’s attention to the walls by decorating other articles of the room and making them your room’s focal point. Bedrooms for example can be given life by simply focusing on the curtains and the beds themselves instead of the wall. Choosing vibrant colors for these articles can help the eye avert its attention to the walls. Living room walls can almost go unnoticed by focusing on the central articles or the room. Put in some live plants for decoration, arrange the furniture so that the rooms center would be the eye’s focal point, you can do all sorts of things in order for the eye to move its attention away from the walls. So what if the walls are completely blank? You have much more color flowing from other articles in the room that can provide the brightness your apartment would ever need.