The value structure of Luc-Olivier Merson is mid-key: quiet, controlled, and cohesive. Cool hues prevail: blues, greens, and greys anchor the palette's emotional temperature. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. #875F4B functions as the palette's exclamation mark: highest chroma, lowest percentage (3.9%). 57 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. This is palette 4 of Luc-Olivier Merson's sequence - a single chapter in a chromatic story told across many works.