Carrie Bradshaw, Sex and the City
Who can forget Carrie (Sarah Jessica Parker) and Big's (Chris Noth) apocalyptic split after the wedding-that-wasn't in the first Sex and the City film? Bradshaw wallowed in her Big-lessness with brunette locks, forgoing her classic golden highlights.
Quinn Fabray, Glee
After a series of disappointing high school milestones—including rough splits with first-love Finn (Cory Monteith) and Puck (Mark Salling) and giving up her baby for adoption—Quinn (Dianna Agron) returned in season three with a shock of pink hair and punk rock garb and makeup.
Peggy Olson, Mad Men
Peggy Olson (Elisabeth Moss) resurfaced at the start of Mad Men's second season with a decidedly different look: After cutting things off with Pete (Vincent Kartheiser) and putting their baby up for adoption, the ad maven returned to the office sans girlish ponytail, a confident short bob and sophisticated makeup in its place.
Felicity Porter, Felicity
In the show's second season, Felicity Porter (Keri Russell) got a cropped cut that stunned fans (and also incited a severe decline in ratings), leaving her long corkscrew curls to the wayside after her relationship with on-and-off boyfriend Ben (Scott Speedman) unraveled.
Donna Pinciotti, That '70s Show
When Donna (Laura Prepon) broke up with her series-long other half, Eric Forman (Topher Grace), after a botched engagement, she decided to ditch her ginger locks—showcasing the buttery blond hue on the final seasons of the show.
Clementine Kruczynski, Eternal Sunshine of the Spotless Mind
In Eternal Sunshine of the Spotless Mind, Clementine's (Kate Winslet) hair color shifts are used to reflect time in the film—different periods of her and Joel's (played by Jim Carrey) relationship and breakup.
Dr. Elliot Reid, Scrubs
Elliot (Sarah Chalke) chopped her hair into a rough bob to assert herself after multiple failed relationships in season three of Scrubs, rocking the short and sexy look for the rest of the season.