A very important service in any auto body shop is the color mixing, painting, and color correction that occurs after repairs have been done. This paint needs to be perfectly matched to the rest of the car or the new paint will be horribly obvious. There are a few tips and tricks experts use to ensure proper color and finish every time.
Auto body shops will use factory paint codes to select the right colors to mix together to get the right shade. This can be found in the owner's manual of each vehicle.
They take this information, mix together whatever paint they need, and get set up in their booth. A booth is necessary so dust won't land on the fresh paint and so wind won't cause overspray or drops on the finish.
The pro painter uses a spray gun for the paint that turns the liquid into a mist to be sprayed on very finely. Movements are slow, controlled, and sweeping to ensure maximum coverage without oversaturating any area. The painter actually fully moves over the edge of the body panel so the edges can be entirely covered.
Consult with your local auto body shops to see if they can help with your paint after repairs, or if they offer custom paint jobs. Some color possibilities with custom jobs are the most beautiful things ever.