Paint a color, visual motif, or textured finish seen elsewhere in the home and use it in the bathroom. Use glamorous wallpaper or an accent wall for smaller spaces.
Add an unexpected feature to your bathroom by including interesting tile or wallpaper designs, furniture that normally goes in another room, or a decorative item.
One of the keys to curing a dark room is having multiple light sources that provide different types of light that will allow you to control the feel of the space.