Art Nouveau is high in key: pale, luminous, and filled with optical air. 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. 25.2% of the palette belongs to #E1D6C5, a concentration that makes it the unmistakable visual centre. The most saturated colour, #CA6943, is reserved to 1.5% of the surface, where it acts as a focal punctuation. A value spread of 64 units gives the palette both depth and air - shadows are genuinely dark, lights genuinely light. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source.