The value structure of Achille Zo is mid-key: quiet, controlled, and cohesive. Achille Zo tilts toward cool - blues and silver-greys carry the structural weight. Muted throughout, the palette achieves its effects through value and temperature rather than chromatic force. The most saturated colour, #9F6638, is reserved to 1.2% of the surface, where it acts as a focal punctuation. At 60 units of value range, the palette has the tonal breadth to sustain complex spatial readings. High luminosity and cool temperature suggest the plein-air condition: unfiltered daylight and open sky. In the context of Achille Zo's full range of palettes, group 4 represents one movement in an ongoing chromatic dialogue.