Values in Thomas Birch rest in the mid-range - neither dramatically lit nor steeped in shadow. Thomas Birch builds on cool foundations: the palette favours the blue-cyan-green arc. Saturation is deliberately withheld - the beauty here lies in the near-monochromatic gradations rather than colour difference. #6D492A functions as the palette's exclamation mark: highest chroma, lowest percentage (4.2%). Spanning 47 units on the value axis, the palette achieves the balance between tonal flatness and fragmentation. 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 Thomas Birch's full range of palettes, group 1 represents one movement in an ongoing chromatic dialogue.