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Colour drenching puts one shade on the walls, the woodwork and the ceiling, and the ceiling is the part that changes your light. With fittings that shine downwards, a mid-shade drench costs about a tenth of the light; an uplighter loses more than half. Choose the light fittings before the paint.
Colour drenching has moved from magazine shoots into ordinary British homes: one colour from the skirting boards to the ceiling, the doors, the architraves and often the radiators too. Paint guides explain how to choose the shade and in what order to paint. They show the result in daylight photographs. None of them says what happens at nine in the evening, when the only light in the room comes from your fittings. That is the question a lighting shop can answer, and the answer surprises most people: how dark the shade is matters less than which way your fittings throw their light. This guide puts a figure on what a drench costs in light, fitting by fitting, works out the lumens to add for a real living room, and says which ceiling shades, finishes and fittings hold up. If you are only painting the ceiling, the fifth wall, the same figures apply.
What colour drenching is, and why the ceiling matters most for light
A full drench covers every surface you would normally paint: walls, ceiling, picture rail, coving, skirting boards, door, architraves and radiator, in one colour or in tones so close that the eye reads one. A tonal drench stays in the same colour family but takes the ceiling a shade or two lighter. A double drench uses two related shades instead of one. The fifth wall is the reverse idea: walls left pale, colour on the ceiling only.
On the walls, the choice is mostly a matter of taste. On the ceiling, it becomes a matter of light. The ceiling makes up a fifth to a quarter of the surfaces in a typical room, and it is the only one that no sofa, curtain or rug ever covers. Everything your fittings send upwards either comes back down off it or is lost there. That is why every lighting calculation assumes a pale ceiling.
The number that measures this is printed on almost every British paint chart: the light reflectance value, or LRV, the share of light a surface sends back on a scale of 0 to 100. BS EN 12464-1, the lighting standard for indoor work places published in the UK by BSI, recommends a ceiling between 0.70 and 0.90 and walls between 0.50 and 0.80, which is an LRV of 70 to 90 overhead and 50 to 80 around you. The standard is written for offices, not living rooms, but it says plainly where the light is expected to bounce. Our guide to hallway colours lists the LRV of each colour family, from 70 to 80 for a white down to 4 for a black. A drench takes the ceiling out of the top of that range, and your light fittings are never told.
How much light colour drenching costs, fitting by fitting
Lighting designers size an installation with utilisation factor tables. For each type of fitting, each room shape and each set of surface reflectances, they give the share of the lamps’ output that actually reaches the room. Read for a room the size of a lounge or a bedroom, those tables say two opposite things.
Light that goes down barely notices the ceiling. Taking the ceiling from LRV 70 to LRV 30 costs 0 to 5 per cent of the useful light, usually 2 to 4. Drench the walls in the same shade as well, from 50 down to 30, and the loss rises to 7 to 14 per cent: with this kind of fitting, the walls cost you more than the ceiling. Even a room painted black on every surface keeps more than three quarters of the light from a downward fitting. Light that goes up depends on the ceiling for everything. The same step from 70 to 30 costs 58 per cent, a step from 80 to 70 already costs 15, and under a black ceiling the indirect share falls to exactly zero.
Your own loss sits between those two extremes, weighted by the share of light each fitting sends upwards:
| Your fitting | Light sent upwards | Colour on the ceiling only (LRV 70 to 30) | Whole room drenched at LRV 30 |
|---|---|---|---|
| Flat ceiling light with a diffuser, downlights | none | 3% lost, lumens unchanged | 7 to 14% lost, add 8 to 16% |
| Pendant open at the top | about a quarter | 17% lost, add 20% | 20 to 25% lost or more, add 25 to 35% |
| Up-and-down wall light | up to half | 30% lost, add 45% | a third lost or more, add 50% or more |
| Uplighter floor lamp, cove, LED strip on top of a unit | almost all | 58% lost, out of reach | more than 58% lost, out of reach |
The first row comes straight from the tables. The other rows are our estimate, pro rata to the light each fitting sends upwards, and they are minimums: darker walls also reduce what the ceiling has to bounce back.
A worked example. Take a 25 m² living room with pale walls. Our guide to how many lumens you need allows 200 lumens per m² for 100 lux, so 5,000 lumens to fit, and adds 20 per cent for mid-tone walls and 40 to 50 per cent for dark ones. Those corrections are the safe figure for the usual mix of shaded lamps and open pendants. Plan the room around downward fittings and the tables let you aim lower: 5,400 to 5,800 lumens for a whole-room drench at LRV 30, or 400 to 800 lumens more, which is 3 to 7 W of extra LED. Paint only the ceiling, in a deep shade, and light the room with pendants open at the top, and you need about 6,000 lumens. Those 1,000 extra lumens are roughly one more bulb of the old 75 W kind, which the Energy Saving Trust puts at 1,050 lumens, or 8 to 9 W of LED: at a unit rate of 25p per kWh, for example, and three hours a night, about £2.50 a year. The bill is not the problem. Finding out after the decorator has gone is.
Uplighters and cove lighting do not survive a dark drench
This is the one mistake that is expensive to put right. An uplighter floor lamp, a cove with a hidden LED strip, a pendant that opens upwards, a strip laid on top of a wardrobe: none of these lights the room. They light the ceiling, and the ceiling lights the room. Once the ceiling is the light source, painting it a deep colour switches that source off, which is exactly what the zero in the tables means. A glass roof after dark behaves like a black ceiling, which is why good conservatory lighting relies on fittings that shine down.
The ceiling also colours the light it sends back. A forest green ceiling returns a greenish light onto faces and food, a terracotta an orange one, a navy a cold grey one. No bulb setting corrects this, because the colour is added on the bounce, after the light has left the lamp.
Our advice is straightforward. Under a mid or deep shade, give up on light aimed at the ceiling and bring it back down. LED strip lights still earn their place where they shine downwards, under a shelf, along a bookcase or beneath a wall cupboard, but not on top of a unit facing a dark ceiling. An uplighter floor lamp gives way to a floor lamp with a shade, or to two table lamps. And if the room has a single ceiling point, a deep drench is the moment to plan a second source.
Light fittings that work in a colour drenched room
- The flat ceiling light with a diffuser. It sits close to the ceiling and sends all of its light downwards: the safest choice under a deep shade, and the only one that loses almost nothing. A flat ceiling light with three or four bulb holders also reaches the lumens you need without hunting for an oversized bulb.
- The pendant closed by a diffuser. Same logic, one step lower, so the light gathers on the table or the coffee table. A frosted base and a closed top stop part of the output escaping upwards to be lost.
- Adjustable spotlights. A bar of spots chooses what the light hits: a bookcase, a picture, a pale chest of drawers. In a drenched room that is the simplest way to win back brightness, by aiming at the few pale surfaces that remain. When a bulb goes, put back one with the same beam angle, as our guide on how to change a spotlight bulb explains, or the pools of light stop matching.
- The wall light that shines up and down loses half its effect: the upper beam that drew a pale fan on a white ceiling disappears on a dark one. Keep it for the lower beam, which grazes the wall and brings out the texture of a matt finish.
Then there is contrast. A white fitting on a navy ceiling stands out like a hole; in black or brass, the same model settles into the colour. The ceiling rose is the other giveaway. White since the house was wired, it shows from the doorway on a dark ceiling: paint the outside of its cover with the ceiling, never the inside, or choose a fitting whose canopy is already dark.
Adding a light point is electrical work. Several sources spread around the room beat one stronger fitting in the middle, but a new wall light or a second ceiling point must meet BS 7671, the IET Wiring Regulations. In England, Part P of the Building Regulations makes a new circuit notifiable, along with any addition or alteration to a circuit within the zones around a bath or shower. Adding a point to an existing lighting circuit elsewhere is not, but our advice is still to use a registered electrician, a member of a competent person scheme such as NICEIC or NAPIT, who certifies the work. Wales has similar rules, while Scotland and Northern Ireland have their own. Swapping one fitting for another on an existing point is a smaller job, done with the circuit switched off at the consumer unit, and Electrical Safety First publishes safety advice for householders who take it on.
Choosing the ceiling shade: LRV bands, warm and cool colours, and the finish
For the walls, the LRV of each colour family is in our hallway guide. Overhead, the family matters less than what each band of LRV still lets your fittings do:
| Shade on the ceiling | LRV, approximately | Uplighter | Open pendant | Flat light, downlights |
|---|---|---|---|---|
| White, soft white | 70 to 80 | works | works | works |
| Coloured whites and pale neutrals: linen, greige, pale pink, very pale blue | 55 to 75 | a little weaker | works | works |
| Mid shades: pale sage, dusty pink, light ochre | 40 to 55 | weakened | add lumens | works |
| Deep shades: forest green, teal, terracotta, deep blue | 10 to 30 | lost | add 20% or more | works, over several points |
| Near-black: navy, charcoal, black | under 15, black at 4 | none | to avoid | works, over several points |
Coloured whites and pale neutrals are the drench that costs nothing. You gain the colour, a downward fitting loses virtually no light and an uplighter still works, only a little weaker. It is the sensible default for a sitting room you use every evening, or for a north-facing room with little daylight.
Warm mid shades improve in the evening, because the warmth of the light adds to the warmth of the pigment. Blues and cool greens fall into the opposite trap: under a 2,700 K bulb they lose their colour and turn grey. Our guide to cool white vs warm white explains what each colour temperature does to a pigment. Choose the bulbs before the tin, and judge a large sample board on the ceiling itself, in the evening, under your own lights, never a card held upright in the shop.
Deep and near-black drenches are a deliberate choice: a cocoon of a bedroom, a dining room used mostly at night, a snug, a downstairs loo. They work on two conditions, fittings that shine downwards and several sources rather than one central point. If the room is already dark during the day, read our guide on how to brighten a dark room before you buy the paint.
The finish counts almost as much as the shade. On the same pigment, a soft sheen or a satin gains a few points of reflectance, but it shows every bump in an old plaster ceiling and mirrors the bulb as a bright patch right beside the fitting, which is very visible on a deep colour. Our advice: matt on the ceiling and walls, eggshell or satinwood on the skirting boards, doors and architraves, which take knocks and wipe clean. In a kitchen or a bathroom, pick a wipeable paint made for damp rooms. The slight change of sheen within one colour is also what stops a drench looking flat.
Does colour drenching make a room look bigger? Low, sloping and high ceilings
The usual promise is that a drench blurs the corners, so a small room looks bigger and a low ceiling higher. Psychologists at the University of Mainz have tested what colour does to the perceived size of a room, using virtual rooms, and their results only half support it. A lighter ceiling makes a room look higher, and so do lighter walls, the two effects adding up. The contrast between walls and ceiling, which architects and the public alike believe to be decisive, makes no difference to the height people perceive. A second study, with coloured ceilings, found that their lightness is what counts: the hue has a very small effect and the saturation virtually none. And the lightness of the ceiling does not change how wide the room looks.
For a drench, this means the shade decides, not the technique. A pale drench, with light walls and a light ceiling, gives the most height of any scheme. A dark drench brings the ceiling down, whatever its colour. Since a dark ceiling does not make a room look narrower, a dark drench feels lower and more enclosed rather than smaller, which is exactly what many people want in a bedroom.
Low ceilings. At 2.4 m or less, a common height in newer homes, a ceiling starts to feel low. Keep the drench pale there, or drench the walls and woodwork and take the ceiling two shades lighter in the same family. The other ways to win height are in our low ceiling lighting ideas: a ceiling with light on it looks further away, and a dark one cannot be lit.
Picture rails and coving. In a Victorian or Edwardian room, taking the ceiling colour down to the picture rail, or 20 to 30 cm onto the walls, brings a very high ceiling down to a comfortable scale. It also removes a band of pale wall exactly where a wall light throws its beam, so in a room that is already dark, keep that band to about 10 cm.
Sloping ceilings. In a loft conversion, the real question is where the colour stops. Paint the slopes and the flat part in one shade, down to the line where they meet the upright walls, and the room reads as a single volume. A pendant there lights a sloping surface from very close, and a deep shade on it switches off a whole zone of the room: two light points work better than one.
High rooms. Above about 3 m, a pendant hangs well below the ceiling and sends most of its light down, while what did travel that far up was largely lost anyway. This is the one case where a near-black ceiling costs very little. The choice of fitting changes too, as our guide to vaulted ceiling lighting explains. Under exposed beams or joists, paint the plaster between them rather than the timber: you keep the pattern and limit the dark surface.
Colour drenching: your questions answered
Should you colour drench the ceiling?
Yes, if the shade is pale or your fittings shine downwards. Leaving the ceiling white breaks the drench, and under a flat ceiling light or a pendant closed by a diffuser, a ceiling at LRV 30 instead of 70 costs only 2 to 4 per cent of the light. If the room depends on an uplighter or cove lighting, keep the ceiling pale or a shade or two lighter than the walls: a dark ceiling cuts that light by more than half.
Can you colour drench without painting the ceiling?
Yes, and it is the safest version for a low or dark room. Drench the walls, skirting boards, doors and radiators, then take the ceiling one or two shades lighter in the same family, or use a coloured white. Research on perceived height shows that a lighter ceiling makes a room look higher and that the contrast with the walls makes no difference, so the lighter ceiling costs the effect nothing.
Does colour drenching work in a small room?
It often works best there, because a small room has fewer corners and edges to blur. A pale or mid drench keeps the most apparent height; a deep one makes the room feel lower and more enclosed, but not narrower. Light it with fittings that shine downwards, add a second source if there is only one ceiling point, and allow about 10 to 20 per cent more lumens for a mid shade.
What are the best colours for colour drenching?
For the light, coloured whites and pale neutrals such as linen, greige or pale pink, at an LRV of 55 to 75: they cost almost nothing with downward fittings and still let an uplighter work. Warm mid shades such as sage, dusty pink or ochre look better in the evening under 2,700 K bulbs. Deep greens, blues and terracottas suit bedrooms and dining rooms, provided every fitting shines downwards and you plan the extra lumens.
What paint finish should you use for colour drenching?
Matt for the ceiling and walls, eggshell or satinwood for the skirting boards, doors and architraves. A sheen gains a little reflectance on the same pigment, but on a ceiling it shows every bump in the plaster and reflects the bulb as a bright patch beside the fitting, which shows up clearly on a deep colour. The small change of sheen between walls and woodwork also gives a one-colour room some depth.
Is colour drenching just a fad?
Nobody can say how long a fashion will last, but the choice that ages best is the one that suits your light. A pale or mid drench costs almost nothing in brightness and is easy to live with. A deep drench is a deliberate choice that needs its fittings planned around it. Repainting takes a weekend; moving or adding a light point is electrical work, so get the lighting right first.
Sources
- BS EN 12464-1, Light and lighting, lighting of work places, part 1, indoor work places: recommended reflectance of 0.70 to 0.90 for the ceiling and 0.50 to 0.80 for the walls. British Standards Institution
- NF C 71-121, simplified method for predetermining illuminance in interiors: utilisation factor tables by class of fitting, room index and reflectance of ceiling, walls and floor, including the class for light sent upwards. Union technique de l’électricité
- Oberfeld D., Hecht H., Fashion versus perception: the impact of surface lightness on the perceived dimensions of interior space, Human Factors, 2011. doi.org/10.1177/0018720811407331
- von Castell C., Hecht H., Oberfeld D., Which attribute of ceiling color influences perceived room height?, Human Factors, 2018. doi.org/10.1177/0018720818789524
- BS 7671, Requirements for Electrical Installations, the IET Wiring Regulations, and Approved Document P, electrical safety in dwellings (England). BSI, the Institution of Engineering and Technology, HM Government
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See also
Mood Lighting: The Three Settings That Really Create It, Room by Room
How to Change a Spotlight Bulb, Even With No Clip or Spring
Conservatory Lighting: Fixings, Lumens and the Black Mirror After Dark
