Tristimulus: Color Lab

About Tristimulus: Color Lab

Tristimulus is a rigorous color-science bench for people who work with color for a living — colorists, print and brand designers, photographers, and vision researchers. It replaces a pile of scattered web tools with one precise, on-device instrument. Everything is computed locally from bundled reference data; nothing is uploaded and no account is required.

CONVERT ACROSS COLOR SPACES
Enter any color and read it instantly across sRGB, Rec.709, Adobe RGB (1998), Display P3 and Rec.2020, alongside CIE XYZ, xyY, L*a*b*, LCh(ab) and L*u*v*. Per-space gamut flags show you exactly where a color clips. See the correlated color temperature and the nearest named color from the bundled dictionaries.

MEASURE COLOR DIFFERENCE
Compare two colors with ΔE76, ΔE94 and the full CIEDE2000 metric, with a plain-language interpretation and a component breakdown (ΔL, ΔC, Δh). A built-in WCAG 2.1 contrast checker rates AA / AAA / large-text / UI thresholds.

CIE CHROMATICITY DIAGRAM
An interactive CIE 1931 chromaticity plot rendered from the actual color-matching functions — spectral locus, line of purples, the Planckian (blackbody) locus, and toggleable gamut triangles for sRGB, Adobe RGB, Display P3, DCI-P3 and Rec.2020. Switch between the 1931 2°, 1964 10° and 2015 observers.

ILLUMINANTS & WHITE-POINT TOOLS
Browse standard illuminant spectral power distributions (A, C, D50–D75, E, the F fluorescent series and LED sources), see each SPD curve, and read its integrated white point and CCT. Chromatically adapt any color between white points using Bradford, CAT02, Von Kries or XYZ scaling.

STUDIO
Generate harmony palettes (complementary, triadic, tetradic, analogous and more) computed in perceptual CIELCh. Simulate protanopia, deuteranopia and tritanopia with the Machado (2009) model. Check legibility against neutral backgrounds at a glance.

REFERENCE LIBRARIES
Search over a thousand named colors across the X11 / CSS, xkcd survey and web-safe dictionaries. Browse the complete Munsell renotation dataset rendered to screen. Preview and apply a collection of real 3D LUTs — space and gamut conversions, chromatic adaptation, color-vision simulation and defined creative grades — with trilinear interpolation on a live color ramp.

BUILT ON REAL DATA
Tristimulus bundles genuine color-science reference data: CIE 1931/1964/2015 color-matching functions at 1 nm, standard illuminant SPDs, the full Munsell renotation set, ColorChecker spectral reflectances and named-color dictionaries — plus a library of computed 3D LUTs. The math (spectral integration, colorimetric transforms, ΔE metrics, chromatic adaptation and LUT interpolation) runs entirely on your device.

- Works fully offline, on a plane or in the field
- No account, no sign-in, no cloud round-trips
- No analytics and no data collection
- Universal app for iPhone and iPad