Cake makeup. It's water-based. You can make it more opaque by layering, or adding less water. Here's the first part of a tutorial
on how to use it, and how it looks. Most people recommend Ben Nye, but Mehron and Kryolan also do cake makeup.
Make sure you allow it to dry, and set with translucent setting powder. You can also spritz your face with setting spray. Good luck!