How colour matching works, and why the paint code is only the start

The paint code on your car gives us the formula the factory used. It doesn't give us the colour your car is today. Years of sun, the batch the factory sprayed, and the way the metallic flake lies all shift the colour, which is why a good match comes from the code plus a spray-out test against the car, plus blending into the next panel. Skip any of those and you get a panel that's "nearly" right, which is the worst kind of wrong.

Step 1: find the code

Every car has a paint code on a plate or sticker: the door jamb, under the bonnet, or in the boot. It identifies the colour (say, a particular white) and lets us look up the mixing formula.

Step 2: pick the variant

Here's the catch. Most codes have several variants, because factories adjusted the colour across production years and plants. A common silver might have half a dozen. Our paint system lists them, and a colour tool or camera reading from the car helps narrow it down. Then we mix the most likely one.

Step 3: spray-out card

The mixed colour goes onto a test card with the same number of coats and the same gun setup we'll use on the car. The card is held against the car in daylight and under the booth lights. If it's off, we adjust the tint and try again. This is the step that separates a match from a guess.

Step 4: blend

Even a perfect mix can show a faint edge where new paint meets old, especially on metallics. So we don't stop at the panel edge. The colour is faded out into the adjoining panel over a hand's width or more, and the whole area is cleared. Your eye can't find a colour step across a gradient, so the repair disappears.

Why metallics and pearls are harder

Solid colours are pigment. Metallics add aluminium flake; pearls add mica. How the flake lies in the paint changes how light bounces off it, so the same mix can look lighter or darker depending on gun distance, air pressure and the number of coats. Three-stage pearls (a base, a translucent pearl mid-coat, then clear) are the hardest, because the number of pearl coats changes the colour. These take more test cards and more care, and usually a wider blend.

Faded cars

A ten-year-old red that's lived outside is not the colour on the plate any more. We match to the car as it is, not the formula, and blend so the new panel sits with its faded neighbours. If the whole car is heavily faded, we'll tell you that a single-panel repair will always be a bit fresher, and talk about options.

Plastic versus metal

The same colour can look different on a plastic bumper and a steel guard because of the primer under it and how the plastic flexes. That's why bumpers get their own spray-out and are blended to the guards where the damage runs to the edge.

What a bad match looks like

A door that's a shade off in the shade. A bumper that's fine in the carport and wrong in the sun. A silver guard where the flake looks coarser than the bonnet. All of these come from mixing the formula, spraying the panel and skipping the test card and blend.

What we do

Code, variant, test card against the car, blend into the next panel, bake, polish. Then we look at it outside, in daylight, before you do. More on the spray painting page.

If you've had a bad match elsewhere, send us a photo. Re-doing a panel properly is a job we see a lot.