A paint coat is a LAYER of paint that is applied to a surface in order to protect it from the elements and give it a decorative finish. It is usually composed of several layers of paint, each of which serves a different purpose. The first LAYER is a primer, which helps the paint adhere to the surface and provides a base for the other layers. The second LAYER is the color coat, which gives the surface its desired color. The third LAYER is the protective topcoat, which helps to seal in the color and provide a durable finish.