"My real hair color is kind of a dark blonde. Now I just have mood hair"

Julia Roberts is most likely describing her hair color changing over time. She is stating that her natural hair color is a dark blonde, but that she has been explore different hair colors. This could be due to her wishing to try something brand-new, or it might be since she remains in a various mood and wishes to reveal that through her hair. It could also be a mix of both. Whatever the factor, Julia Roberts is embracing her altering hair color and having fun with it. She is revealing that it is alright to explore different appearances and that it is a great way to reveal yourself.