Has it been dyed before? You can try temporary color. The ones that wash out. You can't go lighter but you could add some depth. You can also try the sun in stuff. It lightens the hair with citrus juice. Another quick fix or update is to wear accessories in it. Headbands and hats go a long way. You just have to find the style that works for your face. Do you have straight or curly hair? If straight, you could try those foam rods that you sleep in or braiding small sections. If curly you can do the same thing and it will change your texture pattern. :-)
You should try some colorful streaks or a couple of colored hair extensions/clip ins or if that's not your thing you could always do a few highlights. I try all different kinds of hair styles and I keep my hair long, I do braids, pigtails, pigtails with braids, you could do a volume ponytail, if your hair is straight you could use a 3 barrel curling iron to give it a wavy look, looks awesome for summer time. You should try youtube, they have awesome hair tutorials too.