The value structure of Piero della Francesca is mid-key: quiet, controlled, and cohesive. Piero della Francesca 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. The most saturated colour, #C3A480, is reserved to 8.9% of the surface, where it acts as a focal punctuation. Value range is moderate at 51 units - enough contrast for legibility, not so much as to fragment the tonal unity. High luminosity and cool temperature suggest the plein-air condition: unfiltered daylight and open sky. This is palette 4 of Piero della Francesca's sequence - a single chapter in a chromatic story told across many works.