You are free to come up with innovative ideas to decorate the walls of a loft. Usually, a soft and neutral color scheme suits a loft apartment. Try to keep only one color for all the walls, as it gives a sense of coordination and is pleasing to the eyes. However, when it comes to decorating them with art and pictures, you can choose anything that you like. For a traditional feel, hang some nice wooden frames with old photographs or collect some old posters and put them up. If you want your loft to look like a modern-day art gallery, then display a few contemporary paintings. Another great idea is to hang some attractive mirrors on the walls which will also make your loft look larger.