The value structure of Henry Nelson O'Neil is mid-key: quiet, controlled, and cohesive. Cool hues prevail: blues, greens, and greys anchor the palette's emotional temperature. Muted throughout, the palette achieves its effects through value and temperature rather than chromatic force. #936D45 is not a small accent - at 5.0% it qualifies as a major presence and gives the palette its chromatic identity. At 59 units of value range, the palette has the tonal breadth to sustain complex spatial readings. The palette has the character of outdoor light: cool, mid-bright, with colour rendered faithfully rather than expressively. Taken together, these qualities constitute Henry Nelson O'Neil's chromatic voice - distinctive enough to be read across an entire body of work.