The high-key values of Jan van Os give it an effulgent, almost bleached quality. Jan van Os builds on cool foundations: the palette favours the blue-cyan-green arc. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. At 5.6%, #C6C3A9 carries the palette's sharpest chromatic charge: an accent that earns its place precisely because it is withheld. 60 units of value range underpin the palette's structural clarity: the eye always knows where light falls. The palette has the character of outdoor light: cool, mid-bright, with colour rendered faithfully rather than expressively. Palette 1 sits within the larger chromatic argument that Jan van Os's complete body of work advances.