To this day, fans continue to enjoy That '70s Show. It was one of those timeless sitcoms that will last forever. Heck, fans are still coming up with theories about the show, like if Donna and Eric actually ever ended up together... RELATED - The Reason Lisa Robin Kelly's That '70s Show Scenes From Season 6 Needed To Be ReshotFans can get excited, as a lot of the familiar faces will be appearing on That '90s Show. That includes Laura Prepon, who made quite the name for herself on the original.We'll take a look at her audition for the program, along with why she was forced into dying her hair twice, both at the start and towards the end of the series.

Laura Prepon Had A Memorable Audition For That '70s Show

The cast of That '70s Show were all extremely young when it made its network TV debut. Mila Kunis lied about her age while Fez was still in high school...

Nonetheless, they meshed extremely well together, and that included Laura Prepon as Donna. According to the actress, she cemented her position on the show after a memorable last two words.

"One of the things that's really funny is later after I got on the show, I had said to our creators, Bonnie and Terri Turner, 'What was the thing that made you know that I was Donna?'" she recalls alongside EW.

"They said, 'First of all, when you came in, you just were Donna. You were Donna Pinciotti; you were perfect for her.' And at the end of the audition, I looked at them and I said, 'We good?' And I put my hands on the table and I pushed off like a total tomboy. It was just how I got up from my table. They said that sealed the deal."

RELATED - Was Tanya Roberts Loved Or Loathed By The Cast Of That '70s Show?

Looking back at the earlier seasons, Prepon admitted that it is quite surreal to see how young the cast was at the start, though it didn't feel that way while shooting the series.

"We were like, I don't know, 20 when we did this scene and we look like little babies. It's so funny how when you are 20 you feel like you know everything."

The show thrived for several seasons but during the last two, Donna underwent a major transformation, one the show completely ate up.

Laura Prepon Had To Change Her Hair Color For The 2006 Film Karla

It turned out to be a major storyline on the show, Donna changing hair color from her classic red head look, to blonde. She did so for the film Karla but as it turns out, the show-runners loved the change in appearance, so much so that she was asked to keep the look.

According to IMDb, it wasn't the first time the show had input on her hair color. It was the same ordeal at the start of the series.

"Laura Prepon is actually a natural brunette. When she was recruited for the show, she was asked to dye her hair a shade of red for the character Donna. Prepon eventually had to dye her hair blonde for Karla (2006), in which she played the title role."

"As a result, her character Donna Pinciotti was written to have changed hair color for the show's final two seasons. The producers loved her new hair color and begged her to keep it for the show. Prepon had grown to like her blonde hair too and kept the color for years even after the show had finished, but ultimately had to dye her hair black for her show Orange Is the New Black (2013)."

RELATED - Mila Kunis Made A Face After Kissing Danny Masterson In This 'That '70s Show' Outtake

Prepon admitted alongside Women's Health that the topic of her hair color was brought up a lot when she turned blonde, stating "Now that I'm blonde, yeah, totally. People are asking, "Do blondes really have more fun?" My hair can be any color and I'll always have fun."

Laura Prepon Was Recently Back On The Old That '70s Show Set

That's right That '70s Show fans, get excited, as Laura Prepon is set to appear on That '90s Show, the reboot. The series is using familiar props to the original, including the set.

Prepon revealed that taking part in the rebooted series was quite the emotional experience, "It’s so fun. It’s all the same sets. When I first went there, I cried. I’m just like, ‘The nostalgia is so strong and it was such an incredible time in my life.’ I can’t wait for people to see it. I think they’re really, really gonna get a kick out of it."

Fans are eagerly awaiting the return of their favorite characters, which will only add to the series.

NEXT - Did Laura Prepon Bash 'That '70s Show' Co-Star Topher Grace's Kissing Skills?