Auto Air Metallic Colors may be used alone for a metal-like appearance or use as follows: Metallic Colors are best used over Auto Air Base Coat Sealer Dark or 4200 Series Deep Black Graphic Colors. Use as a base for 4200 Series Transparent Graphic Colors for custom metallic blends, or as base for the 4600 Series Candy Colors. Metallic Colors? pigments are heavy and may require vigorous shaking, bottles may be left upside down for a few minutes before shaking.