Thomas Girtin is high-key - luminous, open, and weighted toward light. Thomas Girtin 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. At 49.8%, #D6D0BA functions less as a colour accent and more as a complete atmospheric environment. #476B6E delivers the chromatic peak at only 2.1% - a small shot of colour with outsized visual impact. Spanning 41 units on the value axis, the palette achieves the balance between tonal flatness and fragmentation. High luminosity and cool temperature suggest the plein-air condition: unfiltered daylight and open sky. This is palette 1 of Thomas Girtin's sequence - a single chapter in a chromatic story told across many works.