Olsen turns out for a rockin' rooftop party in New York City. Plus: Gwen Stefani, Prince Harry, Shannen Doherty and more

COLORFUL CHARACTERS

Are they friends or frenemies? America Ferrera and Lindsay Lohan continue to have a great time on the set of Ugly Betty Thursday in New York City. Lohan will appear in five episodes of the ABC hit, which returns on Sept. 25.

See more of your favorite stars all dressed up on set.