How to Colour Match Paint: DIY Methods, Apps & Pro Tricks

Colour matching paint means pinpointing the exact shade, sheen and undertone of an existing surface so a fresh tin — or a custom-filled aerosol — disappears into the background rather than screaming “touch-up”. Whether you’re dealing with a faded living-room wall, a repaired car panel or kitchen cabinets that need an extra coat, the challenge is guaranteeing an identical finish once the paint dries under the lighting.

Thankfully you don’t need a trained eye or an expensive photometer to get it right. From simple paper tests and free colour charts to smartphone apps, scanners and the spectro machines at counters, options exist for any budget and confidence level. This guide walks you through each method step by step, shows you how to collect a sample without leaving an obvious scar and explains how to verify the match before you commit to the full job. Let’s save you from repainting the room.

Step 1: Pinpoint the Original Paint Colour and Finish

Before you even think about buying new paint, lock down the specifics of the old coat. The original brand, colour code and sheen act like sat-nav coordinates; get one figure wrong and you’ll arrive in the wrong shade. Pigments degrade over time and gloss levels flatten, so a ten-year-old “Brilliant White Satin” may now read as a chalky off-white. Knowing the starting formula lets you account for those shifts instead of guessing.

Next, confirm the finish. Matt absorbs light and hides imperfections, eggshell and satin bounce a soft glow, while full gloss is practically a mirror. The same tint looks darker and cooler in matt than in gloss because less light is reflected. Check the surface under varied lighting—north-facing daylight at midday, warm LEDs at night—taking notes each time. This small exercise prevents surprises later and is the foundation of how to colour match paint accurately.

Check for Existing Records

• Raid the garage for leftover tins or tester pots. The label usually lists a batch no., colour ref. and finish.
• Scroll through old email invoices, DIY store loyalty apps or decorator invoices for colour names like “Crown Silk Frost 2”.
• If you find only a cryptic mix code (e.g., D1 45 YY 20/151), jot it down; a paint desk can translate it back into a repeatable formula.

Identify Undertones with Simple Tests

Hold a sheet of bright white printer paper flush against the painted area and step back.

• If the wall suddenly looks slightly yellow, it has a warm undertone.
• A subtle blue or green cast signals a cool undertone.
• If nothing jumps out, you’re likely in neutral territory.

Common traps include greys that reveal a lilac edge once fresh paint dries, or creams that turn peachy under warm bulbs. Spotting these undertones early stops that “close but not close enough” disappointment at the very end.

Step 2: Remove or Capture a Reliable Sample

Spectro machines and hand-held scanners need something concrete to read. A thumb-sized chip of the existing finish (about 25–50 mm square) gives the computer unfiltered pigment data, while a decent photograph is the next best thing when cutting isn’t an option. The trick is harvesting that evidence without leaving a scar you’ll regret and making sure it stays true until you reach the paint desk.

Cutting a Sample from Walls or Woodwork

1. Pick a hidden spot—behind a socket faceplate, skirting return or inside a cupboard.
2. Mask a small square with low-tack tape to protect the surrounding paint.
3. Score around the tape with a fresh craft knife, going just deep enough to lift the top coat.
4. Slip a flexible scraper under the scored edge and peel away the chip.
5. Mark the back with room and position so you can patch it later.

Photographing When Cutting Isn’t Possible

• Shoot in bright natural light; switch off warm bulbs and flash.
• Hold the camera square to the surface to avoid glare.
• Include a sheet of true white paper in frame for reference and take multiple exposures.
• Smartphone matching apps work best with high-resolution images shot this way, but remember even a perfect photo is still an estimate.

Cleaning & Storing the Sample

Wipe off dust, slip the chip into a labelled sandwich bag and keep it flat. Avoid direct sunlight or glovebox heat on the drive to the shop—both can skew colour before the spectrophotometer even starts. Patch the wall with filler once you know the match is spot-on.

Step 3: DIY Colour Matching Methods at Home

Spectro scanners are handy, but you can still get remarkably close with household kit. The goal is to narrow the field to one or two candidates before you commit cash—or repaint an entire wall. Because light dictates perception, run every check in the actual room and repeat at morning, noon and evening. Jot what you see; yesterday’s “definitely warm beige” can look stone-cold under LEDs.

Compare Paint Charts and Swatches

Order free fan decks or A5 cards from Dulux, Crown and Valspar. Hold swatches flat to the surface, creating an L-shape that hides the surrounding colour and sharpens your eye. Shuffle through them at different times of day, then shortlist the three closest matches.

Brush-Out Boards & Testers

Apply two coats from tester pots onto an A4 lining-paper board, label each edge and let it dry fully. Move the board around corners, under ceiling lights and beside soft furnishings to spot unexpected undertones before buying litres.

Mix Leftover Paints for Small Touch-Ups

For micro repairs, blend existing tins on a digital kitchen scale. Note ratios in a notebook—30 ml white eggshell : 5 ml original grey—so you can recreate the mix if it proves perfect.

Step 4: Harness Smartphone Apps and Hand-Held Scanners

If you’d rather stay on the sofa than head to a paint desk, your phone can do a respectable job of detective work. Modern apps analyse pixels, cross-reference thousands of formulas and spit out the nearest retail shade in seconds. It answers the People Also Ask query “Can I take a picture of a paint colour and match it?” with a firm yes—just remember that every camera sensor and light source nudges the result. Treat the app as a short-list generator, not gospel, and you’ll avoid ordering litres of “almost right”.

Even greater accuracy comes from match-stick-sized spectrophotometers that Bluetooth to your phone. These gadgets read reflected light directly from the surface, dodging many of the exposure problems that plague photography. Below are the tools worth knowing.

Top Paint-Matching Apps to Download

• Dulux Visualizer – Live AR overlays, stores colour codes, links to nearest Dulux stockist.
• Valspar “Picture It” – Snap, tap and receive the closest three Valspar mixes plus palette suggestions.
• Adobe Capture – Converts a photo to Hex/RGB, handy for designers who then cross-map the data to manufacturer charts.

How to Capture the Best Image

1. Clean the area; grease dulls colour.
2. Shoot in indirect daylight, flash off.
3. Hold the phone square; avoid shadows.
4. Include a sheet of bright white paper for calibration.
5. Take three shots and use the average result.

Pocket-Size Spectrophotometers

Devices such as the Nix Mini or Datacolor ColorReader press flat to the surface and sample the paint in isolation from ambient light, achieving up to 99 % accuracy. The companion app then lists matching mixes from major UK brands or exports the exact colour values for a custom aerosol order.

Step 5: Visit an In-Store or Online Professional Matching Service

When the colour has to be bang-on first time, hand the job to a spectrophotometer that’s calibrated daily and operated by staff who tint paint all day long. A quick trip to a DIY superstore, decorators’ merchant or a reputable online lab can turn your thumb-sized chip into a freshly shaken tin in under ten minutes. You still need to arrive prepared, though, and understand the quirks that come with different outlets.

What to Bring and Expect at B&Q, Dulux Decorator Centre & Valspar Desks

• Sample: 25–50 mm square, clean and flat.
• Time: scans, formula print-out and mixing usually take 5–10 min.
• Cost: standard paint price plus a small tinting surcharge (£1–£3).
• Caveats: the computer matches colour, not sheen; minimum purchase is often 1 L, so tiny touch-ups may feel pricey.

Ordering Custom Aerosols or Touch-Up Pots Online

Major UK suppliers let you upload the code or post the chip, then dispatch the match nationwide. Aerosols R Us can load that mix into a pro-grade spray can—ideal for cabinet doors, bike frames or metal gates where a roller would leave texture.

Remote Matching Services via Post

If you live miles from a mixing desk, pop the paint chip in a rigid cardboard envelope, use tracked post and insure for its replacement value. Most labs email the formula within 24 hours and ship the tinted paint the same or next day, adding only courier fees.

Step 6: Mix, Test and Verify Before Full Commitment

Think of colour matching like baking: the ingredients may be correct, but you still taste the batter before serving the cake. Ambient temperature, surface porosity and old coats hidden underneath can all nudge a hue. A ten-minute test run lets you catch problems while they’re still wipe-able rather than wall-wide.

Shake, Stir and Label Your Mix

Open the tin and stir bottom to top for a full two minutes; settled pigments skew colour. If you’ve blended multiple leftovers, jot the exact ratio and the date on the lid with a marker—future you will thank you.

Paint a Test Patch in Location

Choose a 30 cm square near eye level, feather the edges with a dry brush and apply two full coats. Observe the patch for at least 24 hours, checking under morning daylight, cloudy afternoon and your usual evening bulbs.

Adjusting If the Match Is Off

Too dark? Stir in measured teaspoons of untinted base or brilliant white. Too light or cool? Add a drop of the nearest darker version of the same hue. Mix thoroughly, retest a smaller patch, and repeat until it disappears into the original surface.

Step 7: Apply the Paint Seamlessly so No One Notices

Even the best colour match looks wrong if the new coat sits higher, lower or glossier than the surrounding surface. The aim now is to equalise porosity, blend edges and leave no visible join.

Preparing the Surface

Lightly wash with sugar soap, rinse and let dry. Key glossy areas with a fine abrasive pad and dust off. If you removed a sample, spot-prime the filler so it soaks paint at the same rate as the old film.

Blend Techniques for Brush & Roller

Work to a natural break—corner, dado rail or window reveal—where the eye expects a shift. Feather the wet edge with long, criss-cross strokes, then lay off in one direction. For rollers, keep a wet edge and overlap by half a sleeve to avoid tramlines.

Spray Application for Furniture, Metal & Detailed Areas

Shake the custom aerosol two minutes; test on scrap. Hold 20 cm away, move parallel, overlapping each pass by roughly 50 %. Build three light coats rather than one heavy pass to dodge sags.

After-Care and Cleaning Up

Respect curing times: 2 hours touch-dry, 5–7 days full hard. Avoid steam, scrubbing or masking tape until cured. Seal leftover paint airtight, label with room and date for future touch-ups.

Match with Confidence

Colour matching paint isn’t wizardry—it’s a repeatable checklist. Identify the original brand, grab a reliable sample or photo, narrow the shade with charts, apps or scanners, then let a pro desk (or your own test board) confirm the mix before you roll, brush or spray. Follow the shake-test-verify routine and you’ll blend repairs, extensions and fresh makeovers so cleanly that no one spots the join. Need an exact hue in a convenient spray can or tiny touch-up pot? Order a precision-filled aerosol from Aerosols R Us and get the match delivered to your door.