Using a sponge, clean the surface of the cultured marble with a bathroom cleaner that is appropriate for cultured marble. Wet a clean towel, wipe the surface thoroughly and then dry it. A clean surface will absorb stain more efficiently than a soiled one.
Sand the surface and wipe off any excess dust. This removes the marble sealant, exposing the surface of the cultured marble.
Apply painter's tape to surfaces that you do not want to stain.
Spray the paint over the marble in a thin, even coat. Allow the paint to dry. Reapply coats until you are satisfied with the color.
Spray marble sealant over the new painted surface and allow it to dry. This will protect the surface from damage.
Remove the painter's tape.