Breathless is a french new wave film starring Jean Seberg as a naive american girl living in Paris. I instantly fell in love with her boyish hair, slicks of eyeliner and stripy tops. There wasn't actually an official costume designer for the movie, instead the director Godard encouraged actors to wear their own clothing and make choices they thought appropriate for each character.
Jean Seberg reminds me a lot of Audrey Hepburn, they both have that authentic classic style that is both chic and timeless.
photos via Google