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Begin with the undertones already present in flooring, stone, tile, timber and large furniture. Decide how the room should feel, narrow the palette to three or four candidates, then paint large sample boards with the intended product and sheen. Move them around the room and view them in morning, afternoon and evening light; a colour chosen from a phone screen or tiny chip is not a reliable final decision.
This guide is written for South Africa, Australia, New Zealand. Always check local codes, product specifications, licences, and site conditions.
Build a simple colour-testing kit
Collect the real materials and useable samples before judging colour names or trends. Your room—not the shop display—provides the final lighting conditions.
- Samples or clear photographs of flooring, worktops, tiles, timber, curtains and the largest furniture pieces.
- Three to four shortlisted colours rather than a wall covered in unrelated options.
- Large white sample boards, ideally A3 size or larger, with a clean border around the test colour.
- Sample pots in the closest available product and sheen to the intended finish.
- Removable tape and labels recording colour name, code, product, sheen and number of coats.
- The actual evening lamps and bulb colour temperatures that will remain after decorating.
How room light changes a colour
Compass advice must be adapted between hemispheres: the sunward side is generally north-facing in South Africa, Australia and New Zealand. Trees, neighbouring buildings, glazing and reflected surfaces can matter as much as orientation.
| Light condition | Typical effect | How to test |
|---|---|---|
| Strong direct daylight | Can wash out pale colours and intensify warm or saturated hues | Check the brightest time of day and watch for glare |
| Cool indirect daylight | Can make grey, blue or green undertones more noticeable | Compare a warmer and a more neutral version beside fixed finishes |
| Low natural light | Whites may look grey and subtle undertones can become muddy | Test an intentional mid-tone as well as the light option |
| Warm evening lamps | Cream, red and yellow notes strengthen while blue notes soften | Judge samples under the actual bulbs at the time the room is used |
| Cool high-output lamps | Can make warm neutrals look cleaner or flatter and cool hues sharper | Confirm colour and surface sheen together; change the bulb first if it is unsuitable |
Step by step
Start with what will not change
Lay flooring, stone, tile, timber, upholstery and curtain samples together. Look past the named colour and identify whether each leans warm, cool, red, yellow, green, blue, muted or clear. The wall colour should relate deliberately to these fixed elements rather than being chosen in isolation.
Define the room’s job and atmosphere
Write three words describing the intended result—calm and soft, crisp and practical, earthy and relaxed, or dark and enveloping. Consider when the room is used, how much visual activity it contains and whether it should connect quietly to an adjacent open-plan space.
Create a small whole-home palette
Choose one or two repeating neutrals or foundational colours, then allow selected rooms or joinery to carry stronger accents. Repetition through halls, ceilings, trim or connected materials creates flow without forcing every room to be identical.
Shortlist against the actual materials
Hold larger manufacturer swatches vertically beside the fixed finishes in the room. Remove candidates whose undertones fight the flooring, worktop or major textiles. Keep three or four options that solve the same brief so the final test is meaningful.
Paint large, labelled sample boards
Apply the recommended number of coats to large white boards and leave a border so the existing wall colour does not distort the comparison. Use the intended sheen where possible because matt, eggshell and higher-sheen finishes reflect light differently. Let samples dry fully before judging.
Move samples through a full lighting cycle
Place one option at a time on different walls, beside trim and near the floor. Review it in morning and afternoon daylight, on overcast and bright days if possible, and under the room’s real evening lamps. Photographing can help comparison, but make the final decision by eye.
Confirm the connected details
Test the chosen wall colour against ceiling, trim, doors, cabinetry and adjacent-room colours. Decide whether trim should contrast, match or use a lighter or deeper related tone. Record the brand, product, code, sheen and batch information before ordering and keep a labelled touch-up quantity.
Expert tips
- Judge one large sample at a time; neighbouring test patches alter how the eye reads each colour.
- Ceilings and trim do not have to be stark white—a related white or tonal colour may sit better with warm materials.
- Sheen changes perceived depth, cleanability and how strongly surface defects catch the light.
- Do not rely on a phone, monitor or printed brochure for an exact colour match.
- If existing bright wall colour contaminates the test, use a large white border or prime the test area first.
- Repeat one or two foundational colours across connected rooms and use accents where the architecture supports them.
Common questions
Why does the paint colour look different on my wall?+
Colour is affected by scale, surrounding colours, surface texture, sheen, daylight, glazing, reflected outdoor colour and lamp temperature. Shop lighting and screens add further variation, which is why a large in-room sample is essential.
Should a dark room always be painted white?+
No. A white with the wrong undertone can look grey or lifeless in weak light. Test a warmer light neutral, an intentional mid-tone and—if it suits the brief—a deeper enveloping colour rather than assuming the palest option will create brightness.
Should I paint samples directly on the wall?+
Moveable boards make it easier to compare different walls and prevent neighbouring patches from influencing one another. A direct wall test can still be useful for confirming texture and sheen, but prime over strong existing colour and apply the specified number of coats.
What is paint LRV?+
Light Reflectance Value describes how much visible light a colour reflects on a scale commonly expressed from low to high. It helps compare relative lightness, but it does not predict undertone, atmosphere or how the colour will behave with your exact daylight and lamps.
What colour should the ceiling and trim be?+
Choose deliberately. A clean contrasting white can sharpen details, a related warm or cool white can harmonise with the walls, and a tonal treatment can reduce visual breaks. Test the combination because the same white can change beside different wall colours.
How many paint colours should a home have?+
There is no correct number. A compact core palette with repeated foundational colours and a few purposeful accents is usually easier to coordinate and touch up than a different unrelated colour in every room.
Sources & further reading
We link to official building-code, government and public-health material where a technical or safety claim needs authoritative context. Local rules and adopted code editions can change.
- Dulux South AfricaHow light affects our favourite paint coloursManufacturer guidance on testing colour in the intended room through changing natural and artificial light.↗
- Dulux AustraliaHow to choose the right paint colourRegional manufacturer guidance covering undertones, lighting, texture and at-home sample testing.↗
- ReseneTesting your paint colours — why sample size mattersNew Zealand and Australian guidance on large samples, orientation, undertones and real project lighting.↗
Stop if the work involves structural uncertainty, hazardous materials, heights, live services, gas, serious water damage, or regulated work. Local rules differ—use an appropriately licensed professional where required.