The value structure of Jan Siberechts is mid-key: quiet, controlled, and cohesive. Jan Siberechts builds on cool foundations: the palette favours the blue-cyan-green arc. The absence of saturated colour is itself an expressive choice: this is a palette of restraint and atmosphere. #353432 at 26.5% of the palette: an overwhelming presence that pulls all other colours into its gravitational field. Only 6.1% is devoted to #8A6B3E, yet that small allocation delivers the palette's entire chromatic tension. The full value range is 56 units: broad enough to build convincing three-dimensional form. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source. In the context of Jan Siberechts's full range of palettes, group 1 represents one movement in an ongoing chromatic dialogue.