Values in Mario Tozzi rest in the mid-range - neither dramatically lit nor steeped in shadow. Blues and teal-greys govern the palette, lending it an aquatic or atmospheric quality. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. #15160B at 27.1% of the palette: an overwhelming presence that pulls all other colours into its gravitational field. The highest-chroma note - #E1A04D - appears at just 2.9%, deployed as a precision accent against the quieter ground. The full value range is 56 units: broad enough to build convincing three-dimensional form. 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 Mario Tozzi's complete body of work advances.