Given the color of the composite material - a grey primer provides a significant amount of coverage over a standard white primer. This allows for less coats of paint over the primer. Grey primer is very common as you can see here.
Using a grey basecoat or primer for these colors has several benefits, including better touch-up, superior hide and more uniform color. You will also save time and money because you can achieve an accurate color match in fewer coats.
How it works
Our base grey primer uses technology that is based on how color pigment scatters and absorbs light. A grey primer creates the ideal balance of light absorption and scattering to achieve the correct color in fewer coats of your color selected. By working inside the color space of the topcoat color, the right basecoat shade allows the topcoat to more fully and more quickly develop its true color.
When ordering primed only shutters and painting yourself or with a professional, you will get to the true color you desired much faster and easier. You also greatly increase the chance of the color on the exterior shutter matching the color of the chip.