Blake Lively has been on the down low since she gave birth to her daughter with actor Ryan Reynolds, whom they named James Reynolds. On the other hand, Nicole Richie's still been chronicling her life on her VH1 reality show, "Candidly Nicole."

But now these two fashion icons are making drastic changes to their hairstyles. Blake Lively is now a brunette. Although it's not a dark brunette most would see, the brown shade is somewhat a mix of blonde and brown.

She's the latest celebrity to try on the newest hair trend called tortoiseshell hair. Basically, tortoiseshell "combines shades of golden blondes, caramels, chestnuts and chocolates," as described by the Huffington Post.

Although she didn't state a reason for the new 'do, this isn't the first time the blonde bombshell has been seen with a different hair color. In fact, she was also a brunette in 2011 for her role in "The Green Lantern" opposite her actor hubby Ryan Reynolds.

So perhaps the new hair hue is for an upcoming project - but everyone will just have to wait and see.

Nicole Richie, on the other hand, has been experimental with her hair color choices. At one point it in 2014, Nicole Richie dyed her locks purple, and she was in fact one of the pioneers who took on the rainbow colored hair trend.

Recently, she's been sporting bright pink hair (she was one of the first celebs to dye it in that shade too).

Last week, she talked about her pink locks with People, "Right now it's kind of fading away, but it's different every time I wash it... to I don't know what. So I'm gonna have to make a decision soon."

But it seems as though Nicole Richie is taking a cue from Kaley Cuoco who recently went from pink and back to blonde. Maybe blondes do have more fun, and Nicole wanted to make a surprising debut at her "Candidly Nicole" season 2 premiere.