Color Lighting Simulator
Test any palette in daylight, warm 2700K light, neutral 4000K LED, and cool 7500K daylight — plus three pro lamps — with hue drift, value collapse, and contrast risk called out, and a light-safe variant when a room demands one.
Comparison view
Your palette, as authored
Your canonical palette, under neutral daylight — the baseline every lamp is measured against.
Warm Lamp
2700KPlanckian 2700 K- Hue driftStrong hue shift — swatch 2 swings 15° (avg 10°).
- Value collapseTonal hierarchy preserved.
- Contrast riskRange holds at 11.3:1 (was 11.1:1).
- ConvergenceAll swatches stay distinguishable.
- Correction limitCorrections recover most but not all of the drift here.
5 swatches could be re-specified for this light
Derive a separate palette that reads as authored under Warm Lamp. Nothing about your canonical palette changes.
Palette report card
Breaks down under Candle / Amber. Get it as a shareable image — swatches under every lamp, grade, and contrast verdict.
View in context
The same palette, doing work
Swatch rows show that a color moved. These show whether it matters — the same swatch keeps the same role in every panel.
How this simulator works
Real lamp spectra, CIE-standard physics, how to read the verdicts — and the FAQ.
What the color lighting simulator does
A hex code describes one appearance of a color: how it looks under neutral noon daylight on a calibrated screen. The rooms your palette will actually live in are lit by warm bulbs, neutral LEDs, and cool window daylight — and each of those lights rewrites the palette. Blues lose their chroma under a 2700K lamp and land as warm grays; whites inherit the lamp's amber; violet swings toward wine; a 4000K LED does the same at half strength, while cool daylight leans everything gently the other way.
This simulator computes those shifts from each lamp's real spectral power distribution — the same CIE-standard physics documented on the Method page — rather than applying a tinted overlay. Paste your palette, sweep the lamps, and the lab reports hue drift, value collapse, and contrast risk per light, grades the palette's overall stability, and derives a light-safe variant when a specific room demands one.
The lights you can test under
- Daylight6500K · CIE D65Neutral noon-daylight reference. The truth baseline every other lamp is measured against.
- Warm Lamp2700K · Planckian 2700 KResidential warm white — the CIE reference spectrum for this CCT. Strong amber weighting starves short wavelengths, so blues lose the light they need to reflect.
- Neutral LED4000K · Measured LED-B3Commercial neutral white — a measured phosphor-converted LED. Blue pump spike plus a broad phosphor hump, typical of 4000 K office and retail lighting.
- Cool daylight7500K · Daylight locus 7500 KNorth-window and overcast daylight. A gentle blue-weighted lift — the quietest lamp here, chromatically close to the D65 reference.
- Gallery Halogen3500K · Planckian 3500 KHigh-CRI museum spotlighting. Continuous blackbody output, so warmth arrives without the spectral gaps that distort pigments.
- Fluorescent4000K · CIE F11Narrow-band office fluorescent — CIE F11's tri-phosphor spikes light only three slices of the spectrum, so colors that matched under daylight can split apart. The metamerism stress test.
- Candle / Amber1900K · Planckian 1900 KCandle and firelight. Almost no short-wavelength output at all, which is why blues and greens go grey and everything collapses toward amber.
How to read the results
Each lamp tab carries a verdict dot — stable, review, or at risk — so the dangerous lights announce themselves before you click. Under a lamp, every swatch shows the color a viewer would actually see, with its drift from the authored value; the notes below call out the failures that matter: a hue that rotated, two colors that converged, a text-and-background pair whose contrast collapsed. The dangerous failures are relationships breaking, not single swatches drifting — which is why the context scenes show the palette doing real work, and why the report card grades structure across every lamp at once.
For the full story of what each light does to each hue family — with every swatch computed by this same engine — read the guide: How colors change under D65, 2700K, 4000K and shade.
Frequently asked questions
- What does a color lighting simulator do?
- It shows how a set of colors will actually look under specific light sources — noon daylight (D65), a warm 2700K bulb, a neutral 4000K LED, open shade, and more — instead of only under the neutral white of your screen. Percevra computes each lamp from its real spectral power distribution, so the shift you see is the shift physics predicts, not a stylized filter.
- Why do colors look different under warm light, LED, and daylight?
- Every light source emits a different mix of wavelengths, and a surface can only reflect the light that reaches it. A warm 2700K bulb emits very little blue, so blues lose chroma and drift toward gray; whites inherit the lamp's amber; a 4000K LED does the same at about half strength; open shade pushes gently the other way, cooling neutrals and lifting blues.
- How do I test my palette under different lighting?
- Paste your hex codes (any separator) or build swatches by hand, then switch between the lamp tabs. For each light you get the simulated swatches, hue-drift and contrast-risk notes, a stability severity per lamp, and context scenes that show the palette doing real work — plus a light-safe variant you can derive when a room demands one.
- Which light should I judge a palette under?
- The light it will live in. A bedroom palette spends its evenings at 2700K; kitchens, offices, and retail mostly live at 4000K; a north-facing room sits in shade light all day. The daylight version on your screen is one appearance out of several — the simulator exists to show you the others before you commit.
- Is the color lighting simulator free?
- Yes. Testing palettes under every lamp, the analysis notes, light-safe variants, and the downloadable report card are all free and run entirely in your browser — no account required.
Start from a palette you already have: extract one from an image, generate one for a use and a light, or pick any color in the color atlas — every color page links back here with its palette loaded.