https://www.tartandictionary.org/tags/spectral-locus/Recent content in Spectral Locus on Tartan DictionaryHugoenTue, 14 Jul 2026 00:00:00 +0000https://www.tartandictionary.org/posts/spectral-locus-oklab/Tue, 14 Jul 2026 00:00:00 +0000https://www.tartandictionary.org/posts/spectral-locus-oklab/<p>The dictionary does all of its colour reasoning in OKLab — classifying shades, measuring ΔTartan, drawing dye-range maps. Those maps always show colours <em>inside</em> a gamut. This story asks the opposite question: where is the <strong>outer edge of all physically possible colour</strong> — the locus of pure monochromatic light, the curve that draws the famous horseshoe of the <a href="https://en.wikipedia.org/wiki/CIE_1931_color_space">CIE 1931 chromaticity diagram</a> — when you plot it in OKLab?</p> <p><img src="oklab_spectral_locus_3d.png" alt="Spectral locus in OKLab: projective view and 3D cone"></p>