How do I match an existing paint colour?

Colour matching is reliable now. What defeats people is that the original paint on the wall has faded, so a perfect match to the tin is a visible mismatch on the wall.

What you'll need

• A sharp knife or a chisel for taking a chip
• A rigid card or tin to carry it flat
• A sample pot for testing

Step by step

1. Look for the original tin first.Lofts, garages and under sinks. The colour name, code and finish on the label is far better than any match, and many people have it without realising.
2. Check for a note from the previous decorator.Inside a cupboard door, on the back of a radiator, or in the meter cupboard. Decorators frequently write the colour somewhere, and previous owners sometimes leave a list.
3. Take a physical chip.Scanners need a flat sample about the size of a coin. Cut one from behind a socket plate, inside a wardrobe or low behind furniture — somewhere that will never be seen.
4. Take it from an unfaded area if you can.Behind a picture or inside a cupboard shows the original colour. But remember the wall you are matching to has faded, so decide which one you actually want.
5. Keep the chip flat and clean.Carry it on card in an envelope. A curled or dirty chip scans badly, and a scanner reading a shadow gives you the wrong colour.
6. Use a merchant with a spectrophotometer.Most large decorating merchants and many DIY sheds have one. It reads the chip and mixes to match. It is far more reliable than holding a card against the wall.
7. Match the finish as well as the colour.The same colour in matt and in eggshell looks like two different colours, because sheen changes how light comes back. Getting the finish wrong is as visible as getting the colour wrong.
8. Understand why it still will not be exact.The paint on your wall has aged, yellowed and been cleaned. A scanner matching a fresh chip gives you the original colour, not the current one, and the difference shows.
9. Buy a sample pot and test it.Paint a patch on the actual wall, let it dry fully, and look at it in daylight and at night. Wet paint is not the colour it dries to.
10. Paint wall to wall, not a patch.Even a good match shows as a patch because of sheen and age differences. Taking the new paint to the natural break at a corner is what makes it invisible.
11. Feather a patch if you must patch.For a small repair, work the paint outward with a nearly dry roller so the edge fades rather than stopping. It is a compromise but far better than a hard edge.
12. Check the colour under your own lighting.Shop lighting is nothing like a north-facing room at four in the afternoon. Metamerism means two paints matching under one light can differ noticeably under another.
13. Record it properly this time.Colour name, code, brand, finish and room, written inside a cupboard door and photographed on your phone. It saves the whole exercise next time.

Tips

• A physical chip beats a photograph every time. Scanners need a flat, clean sample.
• Match the finish as well as the colour — sheen difference reads as a colour difference.
• Paint to the nearest corner. Even a perfect match shows as a patch mid-wall.

Common mistakes

• Matching from a photograph or from memory — Cameras adjust white balance and screens vary enormously. A scanner reading a physical chip is the only reliable method.
• Patching mid-wall with a perfect match — The existing paint has faded and its sheen has changed with cleaning, so even the correct colour reads as a patch. Paint to a corner instead.

If it doesn't work

Questions people ask