How Lighting Affects Paint Colour in Your Home: A London Decorator’s Honest Guide

North Facing Rooms

North facing rooms in the UK get cool, indirect, slightly blue light. It's even and steady, which is why artists used to prefer north facing studios. The downside? It can drain warmth out of cool paint colours. A pale grey that looked soft on the chart can read cold and clinical on a north facing wall.

If you're picking colour for a north facing room, lean warmer than you think you need to. Off-whites with a yellow or red undertone, warm taupes, soft clay tones. Anything with a hint of warmth gets pulled back into balance by that cool natural light.

South Facing Rooms

South facing rooms are the easy ones. Most colours look good here because the light is generous and warm across the day. The trap is that the brightness can wash out very pale shades, particularly chalky whites, leaving them looking flat.

If you've got a south facing room, you can be braver. Deeper colours read beautifully here. Forest greens, inky blues, terracotta, all of those properly saturated heritage shades work because there's enough light to hold them up.

East Facing Rooms

East facing rooms get warm, yellow-tinged light in the morning, then drop into cooler, dimmer light from the afternoon onward. The room you see at breakfast is not the room you see at dinner.

Think about when you actually use the room. A bedroom faces east? Pick a colour that flatters that morning glow. A dining room used mostly in the evening? Sample the colour at the time of day you'll be living in it.

West Facing Rooms

West facing rooms are quiet in the morning and dramatic in the late afternoon, when warm orange light floods in. Reds, oranges and yellows can become intense, almost too rich. Cooler shades, soft greens, pale blues, calm greys, often work better in west facing spaces because they balance that evening warmth.

How Lighting Affects Paint Colour Once the Sun Goes Down

Here's the bit homeowners forget. You'll spend half your time in that room with the curtains shut and the bulbs on. The artificial light matters just as much as the daylight.

Modern LED bulbs are sold by colour temperature, measured in Kelvin (K). The lower the number, the warmer the light. Three numbers worth remembering:

• 2700K is warm white, the soft yellow glow you'd associate with a cosy living room
• 3000K is a notch crisper, often used in kitchens and bathrooms
• 4000K and above is cool white or daylight, which throws a bluish cast

A creamy off-white under a 2700K bulb looks rich and inviting. The same paint under a 4000K bulb can look greyish and a bit dead. I've seen people blame the decorator when the real culprit was a four-pack of cool white bulbs from the supermarket.

The Lighting Industry Association has useful guidance on choosing the right colour temperature for residential spaces, and it's worth a quick read if you're rewiring or replacing fittings.

A Quick Trade Tip on Bulbs

If you're decorating a room, decide on your bulbs before you commit to the paint. Or at the very least, sample the paint under the bulbs you're going to live with. Otherwise you're choosing a colour for a light source you don't actually have.

How to Test Paint Samples Properly

Honestly, this is where most colour disasters get prevented, and it's the practical side of how lighting affects paint colour that homeowners overlook most. The little A4 sample patch stuck next to the skirting board is not enough.

Here's how we do it on jobs where the client wants to be sure:

1. Buy proper sample pots, not just stick on swatches
2. Paint two coats onto a piece of A2 lining paper, not directly onto the wall
3. Move the painted sheet around the room, against different walls, near the window, in the darkest corner
4. Look at it in the morning, at midday, and after sunset with the lights on
5. Live with it for at least 48 hours before deciding

The reason we paint on lining paper rather than straight onto the wall is twofold. You can move it around freely, and you avoid the existing wall colour bleeding through and skewing what you see. Farrow and Ball, Dulux and most of the heritage brands now sell sample pots and peel and stick swatches specifically for this reason.

If you're working with a professional decorator, ask them to brush out three or four shortlisted colours for you on lining paper before you commit. Any decent decorator will happily do this. It's a small bit of work that saves a much bigger headache later.

The Finish Matters Almost as Much as the Colour

One thing that surprises people: the same colour in a matt finish and the same colour in an eggshell finish will look noticeably different on the wall. Sheen reflects light. The more sheen, the more the paint bounces light around, and the lighter and slightly cooler the colour reads.

A few rules of thumb from the tools:

• Matt finishes are forgiving on imperfect walls but absorb light, making colours look deeper
• Eggshell picks up more light and is the practical choice for woodwork and high-traffic areas
• Satin and gloss finishes intensify reflectivity, which can make a colour look brighter but also expose every flaw in the surface underneath

This is why colour matching swatches in a showroom often disappoints once it's on your wall. The showroom card is printed, often slightly glossier than your matt emulsion will be, and lit by retail lighting that's nothing like your living room.

A few Common COlour Mistakes i see in London Homes

After enough years on the tools, you start spotting the same mistakes again and again. Worth sharing them so you don't repeat them.

Picking white because it feels safe. White isn't a single colour. It's a category with hundreds of variations, and the wrong white in the wrong light reads grey, blue, pink or yellow depending on the room. There's no such thing as a default white that works everywhere.

Choosing colour in the shop. Showroom lighting is designed to make paint look appealing under retail conditions, not domestic ones. The same colour will read differently the moment it leaves the shop. Always take samples home.
Forgetting about the ceiling. A ceiling painted brilliant white when the walls are a warm shade can throw cool light back down and undermine the whole scheme. Sometimes a ceiling in a tinted off-white works better than the standard brilliant.
Ignoring the flooring. Wood floors bounce warm tones back up onto the walls. Grey carpet does the opposite. The light reflecting off your floor is part of how lighting affects paint colour in your space, and most homeowners never factor it in.
Sampling for ten minutes, not two days. A quick glance under one light at one time of day tells you almost nothing. Live with the sample.

A Final Word

Light is the silent third party in every paint decision you'll ever make, and that's really what how lighting affects paint colour comes down to. The chart doesn't account for it. The shop doesn't account for it. Even photos online don't account for it. You have to test the colour in your room, at your time of day, under your bulbs, before you commit to a tin big enough to do four walls.

If you're planning a redecoration and you want a second opinion on colour before you go anywhere near a brush, that's exactly the sort of thing we help with on every job. A quick walk through the property, a chat about how you actually use each room, and a few sample brush-outs on lining paper will save you a world of repainting later. Happy to come and take a look if you're anywhere in London.