After there first real fight between Francis and Claire, Claire changed her hair color to black. She kept it like this for few episodes and then changed it back to blonde. What is the underlying meaning of this?

This song looks to be a reference to the actress Sandra Dee, as if herself or the roles she played were that of an "innocent" grown up woman. I'm not much an expert on what roles she played or who she was in real life, but from what I know it's not that their roles were of the type I'm mentioning...