Hippolyte Petitjean is high in key: pale, luminous, and filled with optical air. A distinctly cool atmosphere runs through this palette: sky, water, and mist given colour form. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. #F4CD40 functions as the palette's exclamation mark: highest chroma, lowest percentage (2.5%). From deepest dark to palest light, the palette traverses 57 units of the value scale - a span that creates natural depth. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source. These proportions encode Hippolyte Petitjean's instinctive sense of how much of each quality the eye can hold.