Well, it looks like your hair is fairly light. So going much lighter might not be an option. If you want just a subtle change maybe have your stylist throw in some low-lights. This way you can keep your base color but add more dimension with a darker color (nothing too dark though, honey blonde, golden blonde, dark blonde, along those lines). It would give you a change but it won't be too drastic. This is what I usually do. I almost always do something different everytime I see my stylist. Most of the times they are just little subtle changes.