How to dress for BlackOut House Party?

I am going to my first ever house party tomorrow. I’ve usually been with a girl who hasn’t been comfortable with partying. This time I’m single so I’m also trying to look pretty good. The theme is BlackOut. I don’t really know what to wear. To me I’d assume just all black, but I’m horrible with themes and fashion. It’s tomorrow night so I should be able to buy anything I need.