View the Gallery / 40 Photos »

Fashion conscious Mischa Barton and Rachel Bilson–former co-stars on the tween drama, The O.C.–both turned up at a cocktail party to honor designer Kris Van Assche.

The intimate soiree was sponsored by GQ and Dior Homme and was held at The Cooper Square Hotel Penthouse in New York City. Mischa was dressed in a gold lame jacket, a blouse with three bow ties, black shorts and some yellow heels and appeared to be flying solo.

Bilson, on the other hand, turned up with her rumored fiance, Hayden Christensen, on her arm, wearing a purple velvet bolo jacket and a bright yellow dress.

But Gossip Girl star, Taylor Momsen, really took the cake with her perfectly pleasant shiny pink sheath dress. It would have been a sweet, demure look, were it not paired with her black ankle boots and overly-made-up eyes.

Gallery Info: Hayden Christensen, Rachel Bilson, Rachel Zoe, Roger Berman, Miranda Kerr, Chace Crawford, Kris Van Assche, Sara Paxton, Nico Tortorella, Jesse Metcalfe, Josh Hartnett, Taylor Momsen and Mischa Barton at the event to honor Kris Van Assche sponsored by GQ and Dior Homme.