Frans Arnold Breuhaus de Groot occupies the comfortable middle of the value scale, avoiding both extremes to hold the eye in a sustained middle grey. Blues and teal-greys govern the palette, lending it an aquatic or atmospheric quality. Chroma hovers near zero; colour declares itself through subtle shifts in hue rather than outright saturation. The saturated accent, #51431F, registers at 9.7% - sparse enough to feel like a deliberate surprise. At 63 units of value range, the palette has the tonal breadth to sustain complex spatial readings. High luminosity and cool temperature suggest the plein-air condition: unfiltered daylight and open sky. In the context of Frans Arnold Breuhaus de Groot's full range of palettes, group 4 represents one movement in an ongoing chromatic dialogue.