How repairs work · 9 min read
Professional colour matching starts with your car's paint code, but a good match also accounts for variants within that code, the age and fading of your existing paint, and careful blending into the adjacent panel.
To explain professional colour matching to private car owners so they understand why it is more involved than simply buying paint in the factory code.
Where the paint code comes from
Every car has a paint code recorded by the manufacturer, usually found on a plate or sticker somewhere such as the door shut, bonnet slam panel or boot area. This code identifies the colour that was used when the car was built, and it is the starting point for any colour matching job, but on its own it is not always enough to guarantee a perfect match.
Manufacturers often produce the same paint code in more than one batch, and slight variations can creep in between production runs, which is why two cars that left the factory with the same code can look very slightly different from each other when parked side by side.
Why an older panel is not the factory shade any more
Paint fades and changes very gradually over years of exposure to sunlight, weather and washing, so an eight year old panel will not be exactly the same shade as fresh paint mixed straight from the factory code, even though the underlying code is identical. This is one of the most common reasons a repair can look slightly different when compared with a much older panel next to it, and it is something a skilled colour matcher accounts for rather than ignores.
How a spray-out test card is used
- 01Identify the paint code from the vehicle and pull up the base mixing formula for that code.
- 02Mix a small test batch and spray it onto a card or scrap panel.
- 03Compare the test card against the actual panel on the car in natural daylight.
- 04Adjust the mix in small increments if the tone, depth or metallic content needs fine-tuning.
- 05Repeat until the sprayed sample sits correctly against the existing paint before committing to the full panel.
Metallics and pearls are harder to match than solids
Solid colours are the most straightforward to match, since there is a single pigment layer and no additional variables in how light interacts with the surface. Metallic paints contain tiny flakes that reflect light depending on the angle they settle at during spraying, which means application technique affects the final appearance almost as much as the mix itself.
Pearl finishes add a further layer of complexity, using translucent pigments over a base coat to create depth, and small differences in coat thickness or spray technique can shift how the colour appears under different lighting. Getting these right takes more care and usually more time than a solid colour repair.
Blending into the adjacent panel
Even with an excellent mix, a repaired panel painted edge to edge can sit ever so slightly differently to its neighbour, which is why blending into the adjacent panel is standard practice on most repairs. This means feathering the new paint a little way into the next panel along, so any very small difference in tone tapers gradually rather than presenting as a hard line at the seam.
This technique is particularly important on metallics and pearls, where the angle-dependent sparkle of the paint makes any abrupt transition much easier for the eye to pick out.
Why an aerosol touch-in pen rarely matches
Touch-up pens and aerosols sold under your paint code are mixed to a generic version of that colour, without accounting for the batch variation or the ageing of your specific car's paint. They are also applied by hand rather than sprayed under controlled conditions, which affects coverage, texture and gloss level compared with a professionally sprayed repair.
For small stone chips this is sometimes an acceptable compromise, but for anything more visible, a professionally mixed and tested match, applied and blended correctly, gives a far more reliable result.
What a good match should look like
A good colour match should be very difficult to spot in normal daylight from a typical viewing distance, with no visible line where the repair meets the original paint and a consistent sparkle or sheen across metallic and pearl finishes. It should also hold up when the car is viewed from different angles, rather than only appearing correct from one direction.
If you are unsure whether a repair on your car has been matched properly, comparing the panel in direct daylight, from a couple of different angles, is the simplest way to check.
Where to go next
Worried a repair will not match your paint?
Colour matching is something we take seriously on every job, send us photos of your car and we will explain how we would approach the match, with a free no-obligation estimate.
Questions people ask us
- Where do I find my car's paint code?
- It is usually on a plate or sticker in the door shut, bonnet slam panel or boot area, though the exact location varies by manufacturer.
- Why do two cars with the same paint code look slightly different?
- Manufacturers produce the same code across different batches, and small variations plus the natural fading of older paint mean an exact code is only the starting point for a match.
- Are metallic paints harder to match than solid colours?
- Yes, the reflective flakes in metallic and pearl paints are sensitive to application technique, so they generally take more skill and time to match than a solid colour.
- Will a touch-up pen match my paint properly?
- Not reliably, touch-up pens are mixed to a generic version of your paint code and applied by hand, so they rarely match as closely as a professionally sprayed and blended repair.
Panel beating in a nutshell
- The paint code is the starting point for a match, but not the whole story.
- Ageing and fading mean older panels are not exactly the factory shade any more.
- Metallics and pearls are more difficult to match than solid colours.
- Blending into the next panel helps hide any tiny remaining difference.
- Touch-up pens rarely give as close a match as a professionally sprayed repair.