Every colour has an address — and a starting point for mixing. Explore 13,283 fixed ATLAS references, computed mixing recipes and visible comparisons. Target HLC → Model HLC → H/L/C difference comes first, with Lab values below.
Mix for the light — 38 illuminants, online and offline
Version 0.1.5 is available online and as an offline download. It retains the experimental light-dependent recipe search introduced in version 0.1.4 using the same 38 reference illuminants as the PKL Image Explorer: D50 and D65, 27 fluorescent illuminants and 9 LED illuminants. Start with D50, D65, FL11 and LED-B3, or select the lights relevant to your application.
Choose an Atlas reference in the table, then use Light-dependent mixing to calculate a recipe for that fixed target. Select either the best D50 match or the lowest maximum colour difference across your selected lights. Use the available 31-sample Golden Heavy Body subset or your locally imported spectral palette. Compare the existing and new recipes under all 38 lights, and export the recipe with its light conditions as JSON.
Search uses a simplified Kubelka–Munk S=1 model, up to four components and 100 integer model parts. It does not prove a global optimum. The colour swatches remain D65/sRGB previews; light selection affects the calculation and numerical comparison. Physical calibration and measured mixture accuracy remain open.
Developing spot colours
Choose a fixed HLC address as the target for a custom spot colour. The Mixing Atlas provides a computed starting recipe and shows its model differences. To turn that candidate into a reproducible physical colour, select compatible base colours and binder, calibrate dosing, make a sample on the intended substrate, measure it and adjust the recipe. Current model parts are not calibrated drops or grams; printing-ink and textile suitability have not been established.
The current dataset contains 12,714 HLC model matches (95.72%) and 569 open fields. An open field means no match was found under the current palette, model and search limits. It does not establish fundamental unmixability. The original twelve-illuminant diagnostics remain available alongside the new 38-illuminant comparison. These original HLC coverage counts do not establish success under the new light-dependent search; actual mixing accuracy remains to be tested.
Download and use offline
Download the standalone Mixing Atlas (.html, approximately 39 MB). Save the file and open it in your browser. No installation is required.
Download the WordPress plugin (.zip, approximately 14 MB). Install through Plugins → Add New → Upload Plugin, then use [atlas_clarus_mischatlas]. Release notes for version 0.1.5. Download SHA256SUMS.txt for version 0.1.5.
Try your own spectral palette
Import compatible spectral JSON data locally in your browser, calculate a new candidate and compare it with the existing recipe for the same reference. Your imported file stays in the browser, and the fixed master references and existing recipes are preserved. Use Prepare B/A PNG or Prepare user palette and results JSON, then click the visible Download link to save the file.
Online version 0.1.5: this update corrects stale success messages after reference, light-selection, palette or search-setting changes, including when no search is running. When the reference changes, the previous calculated recipe and its result swatch are cleared, and recipe JSON preparation stays disabled until a new recipe is calculated. The 38-illuminant search introduced in version 0.1.4 remains available.
Sources and validation
ATLAS references: HLC Colour Atlas XL / freieFarbe e.V.; reference system and analysis: ATLAS Clarus, Norbert Woiwod. Source code and source-specific notices on GitHub. Individual material and CIE notices remain visible inside the atlas. Dr Ulrich Backes stated a switch to CC BY-SA in his message of 1 October 2026 without confirming a version number; no version is invented. The PHP wrapper and the added light-dependent mixing code are documented as GPL-2.0-or-later. Material data retains its source-specific terms; no blanket dataset licence is asserted.
Version 0.1.5 · English experimental mixing. GitHub Actions for release commit f94e08e completed the package build, PHP lint and Chromium browser smoke test. The test covers startup, light-dependent recipe search, cancellation, reference changes and the recipe JSON download. The regression checks confirm that changing the reference replaces the previous success message, clears the calculated recipe and result swatch, and disables recipe JSON preparation. The original reference/recipe data, spectra, illuminant data, mixing kernels, candidate search and numerical calculations are unchanged from version 0.1.4. Separate mobile live visual acceptance remains open. Earlier automated results and manual reviews remain evidence for their respective versions; they do not close this mobile acceptance item. These checks verify software behaviour; they do not establish measured colour accuracy, physical repeatability or production approval.