, creating Corrin's look started with intense research. "I spent a few months just doing picture research, collating vast ‘bibles’ of images in chronological order. I make one for each principal royal and the prime minister as they help me to focus on the most significant aspects of their appearance and track how they change over the period of our story," she said in an interview with Netflix.
Hair and makeup kept much of their focus on Spencer's hair, as Hall noted that "Diana’s haircut was what defined her look, even un-styled it is unmistakably her." The team relied on wigs throughout series four, keeping a "Diana cut" for the character that changed in color and styling as the series progressed. "The Princess Diana wigs were very low maintenance," Hall said.