Darkness anchors Jan Cossiers; light is rationed, creating dramatic contrast rather than open air. The dominant temperature is warm, with earth tones and fire-hues setting the emotional key. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. 27.1% of the palette belongs to #271C10, a concentration that makes it the unmistakable visual centre. At 3.9%, #D4AA8E carries the palette's sharpest chromatic charge: an accent that earns its place precisely because it is withheld. The full value range is 58 units: broad enough to build convincing three-dimensional form. The combination of low values, muted chroma, and compressed range is the signature of the Tonalist mode - painting as atmosphere. Palette 4 sits within the larger chromatic argument that Jan Cossiers's complete body of work advances.