Which sentence uses the colon correctly?
Kelly was very excited: about the rock concert her friend won tickets for on the radio. She spent four days trying to put together the perfect outfit. In the end, she settled for something simple: a black tee, ripped jeans, and a headband. In contrast to Kelly: her friend, Maria was dressed rather flamboyantly. She wore shocking pink slacks with a silver tank top. All eyes were on: both the girls that night.