Richard Jack occupies the comfortable middle of the value scale, avoiding both extremes to hold the eye in a sustained middle grey. Richard Jack tilts toward cool - blues and silver-greys carry the structural weight. Every colour is desaturated; the palette proceeds through near-neutrals and gently-coloured greys. The saturated accent, #AD9174, registers at 7.1% - sparse enough to feel like a deliberate surprise. 68 units of value range underpin the palette's structural clarity: the eye always knows where light falls. The mid-to-high key, cool bias, and moderate chroma point to outdoor observation - sky and diffused daylight as the dominant light source. Palette 4 sits within the larger chromatic argument that Richard Jack's complete body of work advances.