See your room before you paint: a guide to the Colour Room

Choosing a colour is hard because a paint card is tiny and a room is not. The walls meet the woodwork, the floor, the curtains and the sofa, and the whole thing changes with the light. A colour that looked perfect on the card can look quite different on four walls.

The Colour Room is a free tool from our design and build team, made to help with exactly that. You set up a room like yours, choose a main colour, and see it dressed three ways, in morning or evening light. Then you keep a mood board, with a measured plan and a kit that lists everything the room is built from. There is nothing to sign up for. Here is how it works, and how to get the most from it.

The Colour Room draws a classic London reception room live, in 3D, and you can turn it to look around. Make it yours first:

• Period or contemporary: cornicing, panelling and sash windows, or clean lines, wide boards and big windows.
• The shape: a rectangle, an L-shaped room, or a room with a bay.
• The size: the width, the depth and the ceiling height, to your own measurements.
• The fireplace wall: with a chimney breast, or with built-in furniture, panelling or a plain wall instead.
• The door: on any wall with room for one, slid along it to where yours is, and opened either way.

Then furnish it, or leave it empty. Choose a sofa, armchairs, a coffee table and a rug, add a floor lamp, a sideboard, a desk, a TV unit or a dining table, and move any of them on the plan. If a piece has no room, the page tells you, which gives a feel for how much a room of your size can hold.

There are twenty-nine main colours in six families, from the everyday whites and off-whites to deep greens, warm earth colours and plums. Most can be made a shade paler or deeper, and each comes with three partner colours, with a line on why each one works. Our guide to colour combinations for London homes sets them all out.

Every colour then dresses the room in three schemes:

• Tonal: the colour everywhere, in deeper and paler versions of itself.
• Contrast: the colour on the walls, with its partner on the curtains, a chair and the cushions.
• Calm: a white room, with the colour kept to the sofa and the joinery.

The scheme sets every surface, from the walls to the rug and the metal, and you can change any one of them. Point at a colour in the palette to see where it goes in the room.

The same colour looks different in a north or a south facing room, and different again after dark. Switch between the two, and between morning and evening, to see how your scheme holds up. Our guide to north and south facing rooms explains why.

Then light it as you would at home. Choose the ceiling lights: a pendant or a chandelier, with or without downlights, or downlights alone. Switch the lamps on or off, and in a period room with a chimney breast, keep the wall lights either side of it or take them out. Set the colour of the light, warm, soft white or cool, and dim it. The section view shows the ceiling and its light. Our guide to lighting a living room covers how to plan it.

Last come the details that decide the character of a room: four panel, three panel or plain doors; torus, ogee, square or shadow gap skirting; coving, from a plain cove to a Victorian cornice or a crisp shadow gap; and a floor of herringbone, planks or tiles, in a choice of timbers, stones and finishes. Our guide to coving, cornice, skirting and doors explains what suits which house.

When the room looks right, download the mood board. It is three pages:

• The room itself, with its palette.
• The plan, measured, with the furniture where you put it.
• The kit: everything the room is built from, grouped the way a builder reads a schedule. The colours and finishes, the doors, skirting and coving, the floor, the fireplace, the lighting and the furniture.

The kit names no brands and no prices. It is a starting specification, and our designers confirm every line with you, paints included, if you take it further. Every choice is also kept in the page's address, so you can bookmark your room or send it to someone.

• Use your own measurements. A colour that suits a large room can overwhelm a small one, and the furniture will only fit if the room is the right size.
• Set the light to match your room, and look at it in the evening too. That is when most living rooms are used.
• Unsure about a colour? Start with the calm scheme. The colour stays on the sofa and the joinery, and it is the easiest scheme to change later.
• Try the details together. A deep cornice, a torus skirting and four panel doors make a room feel period; a shadow gap and plain doors make it contemporary.

Every screen shows colour a little differently, so treat the Colour Room as a way to choose a direction, not a final colour. Before you commit, paint large samples on two walls and look at them in the morning and the evening, next to your floor and fabrics.

When you are ready, bring your mood board to a free consultation. Our interior design team matches every colour to your own light and chooses the paints, fabrics and finishes with you, and our design and build team builds it. If your plans go further than decorating, the Design Studio also has a free estimate for an extension, loft conversion or refurbishment.