Happy birthday, Christina Hendricks! The actress turns 39 today. Although she might be most famous for her role as Joan on AMC’s Mad Men, there’s one feature that helps Hendricks stand out no matter where she goes—her bold, red locks. The actress began dying her naturally blond hair red when she was 10, inventing her now infamous look. “She has the necessary standout personality to go that route,” her colorist, Vanessa Spaeth, previously told InStyle.

Celebrate Hendricks’ birthday by taking a look at how she’s changed throughout the years! (Note: She only gets prettier.)