Robert Henri occupies the comfortable middle of the value scale, avoiding both extremes to hold the eye in a sustained middle grey. Cool tones set the register here - the blues and greens easily outweigh any warm accents. Saturation is deliberately withheld - the beauty here lies in the near-monochromatic gradations rather than colour difference. The saturated accent, #7A5F1D, registers at 5.5% - sparse enough to feel like a deliberate surprise. A value spread of 78 units gives the palette both depth and air - shadows are genuinely dark, lights genuinely light. High luminosity and cool temperature suggest the plein-air condition: unfiltered daylight and open sky. Robert Henri's palette 15 carries its own internal logic while remaining in conversation with the artist's broader colour intelligence.