Things You'll Need
Instructions
Mask over any parts of the model that you don't want painted. If you're using lights on the Monolith, be sure to cover all of these before painting.
Spray a coat of primer over the entire surface of the Monolith to begin. Follow this with several coats of color-shifting paint, waiting for each to dry before spraying the next. The exact number of coats you apply is up to you, though the color-shift effect becomes more dramatic with each coat you add. Spray a gloss coat to finish the base color.
Paint the arches with a color that complements the rest of your Necron army. Gold is a good color choice, contrasting well with the dark purple-green of the body, as long as your other Necrons have gold in their uniforms as well. Paint the gauss guns the same color as the weaponry used by your Necron forces. Define the edges of the body panels with a black pen liner and paint the base in the colors you use for ground foliage.