Pick an Outfit Out

I am heading into NYC Saturday morning for a matinee show and I cannot. decide. what. to wear. I have lots of great summer dresses that would be fun, but they seem much to bright and fun for the seriousness of NEW YORK. I want something comfortable that can last all day because we're going to stay around and grab drinks/dinner with some friends in the evening.

Anyone have any great suggestions!??!? I NEED HELP! :)

Thanks.