On a humid fall day, Hollywood colorist Tracey Cunningham — who tints the tresses of Emma Stone and Lily Aldridge — is in the midst of a four-day residency at the salon, where she — with hairstylist Jen Atkin (who works with Jessica Alba and the Kardashian clan) — will color more than 20 heads a day, some traveling from Egypt, Kuwait and Saudi Arabia for their magic touch.
