“This process took about six weeks, and I probably colored the wig three times before I met Kristen,” Yoshihara said. “When we did the first fitting I knew the color wasn’t right, so I colored it again. In the beginning, [Kristen] didn’t want to wear a wig, I think because she didn’t have experience wearing a very good wig. Then she put this one on, and with the makeup, we got great feedback. She was very happy and confident with it.”

While Princess Diana’s hair was more of a honey blonde color, Stewart’s wigs were created with a more ash blonde look to better fit Stewart’s complexion. Director Pablo Larraín instructed Yoshihara to turn Diana into Kristen Stewart, and not the other way around. The team also decided not to make the wigs beholden to the time period in Diana’s life being depicted in the film. “In 1991 Diana’s hair was quite short, so I first presented photos of that look,” Yoshihara told InStyle. “But Pablo gave me photos of a much earlier hairstyle from 1986. It was a time where Diana was happier and she had longer hair. So I found more images from the same locations of the photos he showed me to match the different angles of the hairstyle.” Yoshihara’s work in “Spencer” has been praised by film critics, as has the costume design by “Little Women” Oscar winner Jacqueline Durran. The film is expected to be an Oscar contender in these craft categories, as well as for Kristen Stewart in the Best Actress race. “Spencer” is now playing in theaters courtesy of Neon. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.