Turns out, dyeing the actor's hair blonde was the least important step in the process.
, and Pickens to learn about turning de Armas into Monroe. It took between two to two and a half hours each morning to apply the hair and makeup simultaneously and around 30 minutes each evening for wig and prosthetic removal and general cleanup. And while Monroe’s signature bleach blonde was certainly a dramatic change for de Armas, it turns out the elements that made the biggest difference were all in the details.
To achieve the film's titular hair color, each wig had three shades of blonde in them, including a shadow root to trick the eye into thinking it’s real hair coming from the scalp. The wigs also featured baby hairs around the hairline.naturally has more growth lengths and usually more baby hairs around the hairline," says Pickens.