The OPI nudes are the shades people ask for by name: Bubble Bath, Put It In Neutral, Samoan Sand, Bare My Soul, Baby, Take a Vow, Hue Is the Artist? and Lisbon Wants Moor. They run from sheer pink-beige to opaque sand, and the sheer ones build from one coat to three, so the finish tag tells you how much coverage to expect.
These are the Nail Lacquer and Infinite Shine bottles. The same nudes in gel are under nude OPI gel polish; the OPI color chart shows all of them side by side so you can pick the undertone that matches your skin.