The value structure of Jean-François Portaels is mid-key: quiet, controlled, and cohesive. Neither warm nor cool has the upper hand here; the equilibrium between the two generates the palette's visual energy. Chroma is moderate: colours carry enough saturation to be read as colour, but the palette stops well short of garish intensity. #C78B5B functions as the palette's exclamation mark: highest chroma, lowest percentage (3.6%). At 43 units across the value scale, the palette keeps contrast readable without letting it dominate. Together these qualities point to the open-air Impressionist method: recording light rather than local colour. Jean-François Portaels's palette 4 carries its own internal logic while remaining in conversation with the artist's broader colour intelligence.