You may not know who Marie Robinson is, but you DEFINITELY know her clients. Emma Stone. Liv Tyler. Anne Hathaway. Kristen Stewart. My girl Sienna Miller. They ALL get their hair colour tended to by Marie, who is widely considered the best colourist in Manhattan (and that’s no small feat). She’s also colour director for Clairol, and here shares seven insider tips on everything from finding the right shade to how often it’s safe to colour.