Paint Science
Jargon Buster
Paint and colour terms in plain English, from undertone and LRV to colour capping and mist coats. Pick a group from the tabs, and follow the links for the full guide where we have one.
Colour language
10 terms
- Undertone
- The subtle colour hiding beneath a paint’s apparent colour, most visible in large areas or in certain lights. A grey can carry a green, blue, purple or pink undertone, which is why two greys that look identical in a tin can look very different on a wall. Undertones become obvious when a colour is placed next to a true neutral.Read more: How undertones decide what goes together
- Hue
- The colour family a paint belongs to: red, yellow, green, blue and so on. Everything else in colour description, such as lightness, saturation and temperature, is measured against the hue.
- Chroma
- How intense or saturated a colour is. A tomato red is high chroma; a brick red is mid; a putty colour is very low chroma. Colours with high chroma feel more energetic and can look stronger on walls than on a small sample card.Read more: Clean and dirty colours
- Tint, tone and shade
- A tint is a colour lightened with white, a shade is darkened with black, and a tone is greyed down. Most sophisticated interior palettes are tones and tints rather than pure hues.
- Warm vs cool
- Colours are grouped by the temperature they suggest: reds, oranges and yellows read warm; blues, greens and violets read cool. Temperature is relative: a green can be warm (yellow-based) or cool (blue-based), which matters more than the label.Read more: Warm and cool colours
- Neutral
- A colour with very low chroma: whites, greys, beiges, greiges and stones. Few neutrals are truly neutral; most carry an undertone from a parent hue, which is why the neutral that looked right in the showroom can clash at home.Read more: Neutral paint colours
- Greige
- A grey-beige hybrid: the warmth of beige with the calm of grey. It became popular because it bridges cool grey floors and fittings with warmer furnishings.Read more: Greige paint colours
- Muted colour
- A colour with its intensity reduced, usually by grey or a complementary colour. Muted palettes feel restful and historic; saturated palettes feel contemporary and bold.Read more: Clean and dirty colours
- Jewel tones
- Deep, rich, saturated colours named after gemstones: emerald, sapphire, ruby, amethyst. They work best with confident lighting, because in dim rooms they can read almost black.Read more: Jewel tone paint colours
- Pastels
- Soft tints made by lightening a colour well towards white: clean, mid-to-light shades with low intensity. They suit rooms that need light without the starkness of pure white.Read more: Pastel paint colours
Design techniques
9 terms
- Colour drenching
- Painting walls, woodwork, ceiling and sometimes radiators in one single colour. The effect makes a room feel considered and can make small rooms feel taller, because the eye isn’t interrupted by contrast.Read more: Colour drenching guide
- Colour capping
- Painting a room in two or three shades from one colour family, usually lightest on the walls, a mid tone on the cornice or picture rail and the deepest on the ceiling, so the colour deepens as the eye rises. It differs from drenching, which uses one colour everywhere.Read more: Colour capping guide
- Cloud capping
- A softer variant of capping: walls, woodwork and doors in one colour, with the ceiling in a soft white or pale neutral that shares the wall colour’s undertone, instead of a stark brilliant white.Read more: Colour capping guide
- Picture rail
- A moulded rail fixed to the wall at picture height, traditionally around three-quarters of the way up. Originally for hanging pictures from picture wire; today often used as a natural break line for two-tone or capping schemes.
- Two-tone walls
- Splitting a wall horizontally into two colours, usually darker below (more forgiving of scuffs) and lighter above. It can be split at a dado line, a picture rail or a chosen height.Read more: Two-tone walls guide
- Accent wall
- One wall painted in a contrasting or stronger colour than the rest of the room. It creates a focal point but works best when the accent colour is already present elsewhere in the room.Read more: Feature wall ideas
- The 60-30-10 rule
- A classic scheme guide: roughly 60% of the room in a dominant colour (usually the walls), 30% in a secondary colour (upholstery, curtains, rugs) and 10% in an accent. It is a starting proportion, not a law.Read more: The 60-30-10 rule
- Complementary colours
- Colours opposite each other on the colour wheel, such as blue and orange. Used well they energise a scheme; used heavily they fight, so decorators usually pair a strong complementary with muted versions.Read more: Colour theory explained
- Analogous colours
- Colours sitting next to each other on the colour wheel, for example blue, blue-green and green. These schemes feel harmonious and are the easiest to live with.Read more: Colour theory explained
Light and perception
6 terms
- LRV (light reflectance value)
- A 0 to 100 measure of how much light a painted surface reflects: 0 absorbs all light, 100 reflects it all, and our own palette runs from 3 to 95. LRV predicts how light or heavy a colour will feel in a room and how much it will brighten a dim space, and the same colour can feel dramatically different in a north- versus south-facing room. Our colour pages list each shade’s LRV, calculated from measured Lab colour data.Read more: LRV explained
- Metamerism
- When two colours match under one light source but not another, because the samples reflect light differently across the spectrum. It is one reason a paint can match a sofa in daylight but clash under evening lamps.Read more: CRI and metamerism
- Colour constancy and light-dependent shift
- The eye adapts to surrounding light, so a paint’s apparent colour changes through the day. North-facing rooms receive cool, even light that can flatten warm undertones; south-facing rooms receive warm, strong light that can brighten or yellow pale colours.Read more: Colours for north-facing rooms
- Colour Rendering Index (CRI)
- A 0 to 100 score for how faithfully a light source reveals colours compared with a reference light. Low-CRI bulbs, typical of older budget LEDs, can make paint look dull or shift its undertones; CRI 90+ is worth choosing where colour accuracy matters.Read more: CRI explained
- Kelvin (colour temperature)
- The warmth or coolness of white light, measured in kelvin (K). Around 2700K is a warm, candle-like white; 3000K a softer warm white; 4000K a cooler, neutral white. Bulb choice can visibly change a paint colour, especially whites and neutrals.Read more: 2700K vs 3000K vs 4000K
- Lumens vs watts
- Watts measure energy used, not brightness; lumens measure light output. LED packaging shows lumens, and matching a room’s lumen level matters more than matching wattage when replacing older bulbs.Read more: Brightness, lumens and dimming
Paint technology
10 terms
- VOC (volatile organic compound)
- Solvents released from paint as it dries. VOCs contribute to indoor odour and, at high levels, air quality concerns; UK and EU decorating paints are regulated with VOC content limits by product type. Water-based modern paints sit far lower than older solvent-borne paints, and “low-VOC” or “zero-VOC” claims should be checked against the stated grams-per-litre figure.Read more: Low-VOC paint explained
- Sheen levels (matt, eggshell, satin, gloss)
- How much light a dried paint film reflects. Matt scatters light and hides wall imperfections; eggshell and satin are mid-sheen finishes common for woodwork and kitchens; gloss reflects most and shows surface flaws most. Higher sheens were traditionally the tougher choice, but modern scrubbable matts close much of that gap.Read more: Our finishes explained
- Primer and undercoat
- A primer seals and prepares a surface for paint adhesion; an undercoat builds an even base colour. On bare or previously unfinished surfaces, and on tricky substrates like uPVC, composite or laminate, a separate primer is usually needed, and choosing the right one is often the difference between paint that lasts and paint that peels. Cameron Colours paint is self-priming on those difficult surfaces once they’re correctly prepared (cleaned, degreased and keyed as directed), so there’s no separate primer to buy. Full adhesion builds over the seven-day cure.Read more: Painting laminate without peeling
- Mist coat
- A thinned first coat of emulsion applied to fresh, absorbent plaster so it doesn’t pull water out of the topcoats. Skipping it is a common cause of patchy, flaking emulsion on new plaster.Read more: Mist coat on new plaster
- Opacity and coverage
- How well a paint hides the surface beneath it in a given number of coats. Opacity depends on pigment type and loading, and this is where high pigment loading earns its keep: a paint with strong opacity covers in fewer coats, so most repaints, including lighter shades over darker walls, don’t need a tinted undercoat. Cameron Colours shades are formulated for exactly that: honest coverage without a primer-and-undercoat shopping list. Depending on the surface and the size of the colour change, a third coat may sometimes be needed.
- Drying vs curing
- Drying is when the surface is touch-dry; curing is when the film reaches full hardness and scrub resistance, which for water-based paints can take days to weeks. Furniture and cleaning should stay off a newly painted surface until it has cured, even when it feels dry.Read more: Why paint stays tacky
- Touching up
- Repainting a small damaged or filled area so it blends with the paint around it. Use the leftover paint from the original job, mixed thoroughly from the bottom of the tin, and apply it the same way the surface was first painted: roll it if the surface was rolled.Read more: How to touch up paint
- Recoat time
- The minimum interval before applying the next coat, set so the previous coat can accept another without lifting or wrinkling. It varies by product, temperature and humidity: cold, damp rooms slow everything down.
- Water-based (acrylic/emulsion) vs solvent-borne (alkyd)
- Water-based paints thin with water, have low odour, recoat faster and now dominate decorating; older solvent-borne alkyds (traditional oil-based gloss) level beautifully but carry high VOCs and yellow over time. Modern acrylics and hybrid “alkyd-look” water-based finishes are designed to close that gap.
- Pigment
- The finely ground particles that give paint its colour. The choice of pigment affects not just hue but opacity, lightfastness and cost: earth pigments give muted, historical tones, while modern organic pigments deliver bright, clean colour but can need white or transparent bases to mix correctly.Read more: Pigments in Paint Science