DIY

Room Colour Visualiser

Your mixed colours, on real walls, under real light
Path-traced preview
ready

Room

Size

Surfaces

Walls
Accent wall
Ceiling
Woodwork — skirting, coving, window frame
Floor

Furnishing

Light

Ceiling light
Wall reflectance
Floor area

Quality

0
Samples — higher is cleaner, and slower
Detail
warming up
drag to look around

What you are looking at

Light
Traced, not faked
Bounces
4
Why walls tint each other
Wall sheen
A roughness, not a label
Sheen

Why the same colour looks like two different colours

SheenRoughnessWhat you seeWhere it earns its keep
Matt0.95No visible reflectionCeilings and imperfect walls — hides flaws best
Eggshell0.60A faint sideways glow near the windowLiving rooms and bedrooms
Satin0.38A soft wide highlightHallways and kitchens — wipeable
Semi-gloss0.22A clear soft-edged reflection of the windowWoodwork and bathrooms
Gloss0.08A sharp mirror imageSkirting and frames — shows every imperfection
Roughness is the parameter in the microfacet model that actually controls how tight a reflection is. The mapping above is illustrative rather than a measurement of any product: paint is sold by gloss units read at a fixed angle, and manufacturers do not agree on where one name stops and the next begins.
Field notes

Reading a preview honestly

A screen cannot show you a paint colour

Your monitor emits light; a wall reflects it. Two people looking at this page see different colours, because their screens differ and neither is calibrated. Compare choices against each other here, then buy a tester pot before you commit.

Colour bleeding is real, and it is strong

A saturated wall throws its own colour onto the ceiling and the floor. That is why a bold colour often feels heavier once four walls are done than the tester patch suggested. This preview models it; a flat swatch cannot.

Small rooms bounce more

Opposite walls are closer together, so light makes more short trips between them and the colour compounds. Try the same colour at each of the three sizes — the small room reads noticeably more saturated.

Woodwork is doing more than you think

Skirting, coving and frames are usually the brightest, glossiest surfaces in the room. They frame every wall, and dropping them from brilliant white to a soft off-white changes how the wall colour reads against them.

How it works

Light bounces, and that is the whole point

Rays leave the camera, bounce around the room up to four times, and stop only when they find their way out of the window or reach a light. Nothing is painted on afterwards. That matters because the single biggest reason a colour surprises people is colour bleeding: a saturated wall throws its own colour onto the ceiling, the floor and the wall opposite, so four walls of a colour read stronger and warmer than the tester patch you judged it by. A flat swatch cannot show you that. This can.

Worked example

Put a strong terracotta on the walls and a plain white on the ceiling. The ceiling does not stay white — it picks up a warm cast, strongest where it meets the walls. Switch the walls to sage and the same ceiling goes faintly green. Neither is a trick of the rendering; it is what the room will do.

Why does the wall with the window in it look darker?

Because it is lit at a glancing angle while the wall opposite catches the light square-on. Same tin, same coat, sometimes a startling difference. It is worth dragging the view round before judging a colour — and worth remembering when someone says the paint "looks different on that wall".

Does sheen really change the colour?

It changes what you see, which is the same thing in practice. Gloss reflects the light source itself — usually whiter and brighter than the paint — so a glossy wall reads lighter and less saturated where that reflection lands, and shows every roller mark and filled dent. Matt scatters almost everything and shows the pigment more honestly.

Why is the image speckled at first?

It is averaging random light paths, so it starts noisy and resolves as samples accumulate. More samples means a cleaner picture and a longer wait; the Quality panel lets you choose. Nothing about the colour changes as it converges — only the noise.

Why does the same colour look stronger in the small room?

Opposite walls are closer together, so light makes more short trips between them and the colour compounds with each bounce. It is the same effect that makes a bold colour feel heavier in a box room than on a tester patch.

Can I match a specific brand's colour with this?

No, and you should distrust anything that claims otherwise on a screen. The colours here come from the mixing model next door, not from any manufacturer's product, and your monitor is not calibrated to anyone's. Use this to compare options against each other, then buy the tester pot.

What this page assumes

A rectangular room with one window, four bounces of light, and a single sky model — enough to show how a colour behaves, not a lighting simulation of your house. Surfaces are perfectly flat and uniformly coated, so it cannot show brush texture, patchy coverage, or the sheen difference between a first and second coat. Skirting, coving and window frames are drawn as flat bands rather than mouldings, so they carry the right colour and sheen but not a profile. Furniture is blocked in for scale and for the light it bounces, not modelled. Sheen is mapped to roughness on an illustrative scale rather than measured gloss units, and paint colours come from the mixing model rather than from any manufacturer's product. Screen colour is emitted light rather than reflected pigment, so treat this as a way to compare options rather than as a match — test on the actual wall before buying.

A preview, not a match. Compare colours against each other here, then put a tester pot on the actual wall and look at it at three different times of day.
Version history · unchanged

No changes to this tool’s own behaviour since the earliest archived release (v2.2). The full history for the site is in the changelog.