Go as big as you can to add a more dramatic effect to the room. The color is a must to either match other decor such as gold or silver or buy as an accent color to off set the main color in the bathroom. The shades come in colors.
Lighting can be a focal point in a room. A piece of art rather then just something that produces light for a room. Check out The Lamp Genie based in Thousand Oaks, CA for a unique approach to lighting.