How does colour matching work in car refinishing?

1Find the paint code

Every car’s colour is identified by a paint code from the manufacturer. The code is usually on the maker’s label in the driver’s door jamb, under the bonnet or in the boot; where exactly depends on the make and model.

If the label cannot be read, the manufacturer’s service records can give the paint code from the vehicle identification number (VIN). Once you have the code, request the formula through the paint code form on our Automotive Refinish page.

2Choose the right variant

The same paint code may have been applied in slightly different shades at different plants or in different production years. That is why paint makers publish several variant formulas for one code: slightly lighter, darker, yellower or bluer. The right variant is chosen by holding variant chips against the car or by measuring with a spectrophotometer.

3Measurement and digital colour tools

A spectrophotometer measures the colour of a painted surface from several angles and suggests the closest formula in the paint maker’s colour software. It is most useful on cars whose code cannot be read, whose paint has faded in the sun over the years or that have been repainted before. Clean the surface before measuring and polish it lightly if needed; a dirty or oxidised surface gives misleading results.

4Weigh the formula and spray a test card

1. 01
   Weigh the formula

   Weigh the formula on the mixing system’s precision scale, in the order of the components. Weighing errors affect the colour more in small quantities.

2. 02
   Spray a test card

   Apply the colour to a test card with the same gun settings, pressure and number of coats you will use on the car; in a clearcoat system, clear the card too.

3. 03
   Let it dry, then compare

   Let the card dry completely. Wet paint and dry paint do not look the same.

4. 04
   Look in daylight

   Hold the card next to the cleaned panel and compare in daylight or under a daylight lamp, face-on and from the side.

5Take care with metallic and pearl colours

With metallic and pearl colours the shade changes with the viewing angle: the colour seen face-on and the colour seen from the side (the flop) can differ. How the aluminium and pearl pigments settle depends on gun distance, pressure and film thickness, so even the same formula can look different when applied differently.

With these colours, even when the formula is right, blending the repaired panel into the neighbouring panels stops the eye from catching a small difference.

Common mistakes

• Spraying the car without a test card
• Judging the colour only under workshop lighting
• Comparing wet paint with a dry panel
• Using paint that has not been stirred or strained properly
• Measuring on a dirty or oxidised surface

Frequently asked questions