F1: Very Fair to Light. Think Michelle Williams, Cate Blanchet, or Ginnifer Goodwin. What is Nail Foundation and How Should it be Worn? We all know what foundation does for the face. Now, for the first time ever, we ve developed a line of full coverage nudes that extends the exact same benefits for nails. Applying Nail Foundation allows the nails to be fully covered from any imperfections while still showing off a simple, clean and very modern effect. We wanted to create an easy way for women to feel confident about their nails. You can wear Nail Foundation alone.