What are dirty martini nails exactly? It’s not just green polish, but a specific nail art design with a subtle Spanish olive accent that has slowly taken over mood boards, worn by celebrities, like Hailey Bieber, and seen in trendy nail salons from NYC to LA. To dig deeper into the trend — and learn exactly how ask for it — we went directly to the source, the artist who created the martini olive art months before it became trendy, Betina Goldstein.