Charlize Theron is nominated for outstanding performance by a female actor in a leading role for her performance as Megyn Kelly in Bombshell

Charlize Theron wore some dazzling diamonds at the Screen Actors Guild Awards — in her hair!

The actress, who is nominated for outstanding performance by a female actor in a leading role for her performance as Megyn Kelly in Bombshell, admits she didn’t have time to hit the hair salon before the awards ceremony. But she decided to turn it into a major fashion moment.

With her hair parted in the center and pulled back into a sleek up-do, Theron’s dark roots were slightly visible, so her hairstylist Adir Abergel suggested she add some jewels to complete the style.

Charlize Theron

“I didn’t have time to do my roots. So my lovely friend Adir said, ‘Why don’t we throw a Tiffany necklace or bracelet in there,'” Theron tells PEOPLE on the SAG Awards red carpet.

Her hair wasn’t the only part of Theron’s look with a little bit of glitz. The actress, 44, hit the red carpet in a Givenchy Haute Couture sparkling silver hand-embroidered crop top with a belted black maxi skirt, teamed with platform sandals and a clutch (also by the label) and an over 3-carat Tiffany & Co. Victoria line diamond bracelet in her hair – worth $15,500.

In fact, she sparkled in $4 million worth of Tiffany & Co. diamonds, including stunning over 11 carat Tiffany diamond earrings, paired with exquisite Tiffany diamond bracelets and rings.

26th Annual Screen Actors Guild Awards, Arrivals, Shrine Auditorium, Los Angeles, USA - 19 Jan 2020

Watch the PEOPLE, Entertainment Weekly & TNT Red Carpet Live: 26th Screen Actors Guild Awards on Sunday starting at 5:30 p.m. ET/2:30 p.m. PT on Stay tuned for the annual SAG Awards airing on TNT and TBS at 8 p.m. ET/5 p.m. PT.

The SAG nominee opened up to PEOPLE about researching for her role as Kelly for the acclaimed film centered on the Fox News drama. “The good thing about playing someone who is that well-known is that there’s a lot of footage. There’s a lot to read about. There’s a lot for your research,” she says.

Theron adds: “The voice… I wasn’t even convinced we were going to get anywhere. But I have an amazing dialect coach, Karla Meyer. There should be a nomination for dialect coaches and she would win it this year! I still don’t know how she does it.”

Although Theron recently lost at the Golden Globes and Critics’ Choice Awards, she did earn an Academy Award nomination for Bombshell earlier this week. “It’s been a thrilling couple of weeks,” she said after the news was announced.

In the Best Actress category at the Oscars, Theron is up against Renée Zellweger (Judy), Scarlett Johansson (Marriage Story), Saoirse Ronan (Little Women) and Cynthia Erivo (Harriet).

The 26th Annual Screen Actors Guild Awards are airing live Sunday starting at 8 p.m. ET on TNT and TBS.