Gilbert Jackson is built on dark foundations, with values clustered toward shadow. Cool hues prevail: blues, greens, and greys anchor the palette's emotional temperature. All colours lean toward grey, building depth through value rather than colour punch. #0A0A09 at 31.2% of the palette: an overwhelming presence that pulls all other colours into its gravitational field. #A27141 delivers the chromatic peak at only 1.9% - a small shot of colour with outsized visual impact. The full value range is 66 units: broad enough to build convincing three-dimensional form. The combination of low values, muted chroma, and compressed range is the signature of the Tonalist mode - painting as atmosphere. In the context of Gilbert Jackson's full range of palettes, group 4 represents one movement in an ongoing chromatic dialogue.