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. Chroma hovers near zero; colour declares itself through subtle shifts in hue rather than outright saturation. At 3.5%, #BE7A59 carries the palette's sharpest chromatic charge: an accent that earns its place precisely because it is withheld. The value range of 54 units sits in the comfortable middle: enough depth, enough light, neither extreme. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source.