Auto Air Semi-Opaque Colors are base coat colors which can be used alone and cleared or used as a base coat for 4300, 4400, 4500 Series to achieve special color effects. Other uses include: 1) Tint with Transparent Colors for custom blends by either directly mixing the colors or layering light coats of Transparent Colors over Semi-Opaque Colors 2) Use as the underlying coat for other Auto Air Colors.