Much has been written about the Jean Seberg Style, but what is it? Perhaps it is her hair. Her short hairstyle caused a sensation when unveiled in 1957 for Saint Joan, but it was slightly modified and made more stylish with blond highlights in subsequent films through 1960. Then she grew her hair out and returned to her natural light brown hair color for a couple of years while dating Romain Gary and appearing in the films Congo Vivo and In the French Style.
She went back to blonde in 1963 but modified "la Seberg coup" (as it was known in France) to a bit fuller and longer look, parted on the side. During the 1965 Moment to Moment era it was perfectly coifed for public events to withstand the strongest wind--which was not atypical for that time. She also went back to a brunette color for filming A Fine Madness (perhaps because there were enough blondes already in the film!).
From roughly 1966, and for several years thereafter, Jean primarily wore her hair blonde and short as it required little maintenance. She would alternate styles throughout the 1970s as well. At the time of her death, her hair was not the close-cropped look of Breathless, but a fuller look. It's interesting to note in many of her 1960s American films, she wore a wig--Lilith, Paint Your Wagon, Macho Callahan (partially), Airport. Only Pendulum showcased the Seberg Style, while the reverse can be said of a majority her European films.
Others feel the Seberg Style was embodied in the clothes Jean wore--especially those in Breathless. The peddle pushers and white top while walking down the Champ Elysee is an iconic moment in motion picture history. In her films, she dressed in everything from haute couture to corsets with petticoats to non-descript designs. Off-screen she dressed for the occasion including designer gowns, both long and short, as evident by the many photographs taken of Jean at events.
Perhaps the Seberg Style is a combination of both hairstyles and fashion, but one must add the uniqueness of her beauty, poise and elegance, her down-to-earth sensibility (and Iowa stubbornness as outsiders sometime say about Iowans) as well as her intelligence and kindness to this mystique known as the Jean Seberg Style.