The value structure of Maurice Poirson is mid-key: quiet, controlled, and cohesive. Cool tones set the register here - the blues and greens easily outweigh any warm accents. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. The saturated accent, #805431, registers at 9.1% - sparse enough to feel like a deliberate surprise. 69 units of value range underpin the palette's structural clarity: the eye always knows where light falls. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source. Palette 4 sits within the larger chromatic argument that Maurice Poirson's complete body of work advances.