The value structure of Archibald Thorburn is mid-key: quiet, controlled, and cohesive. Temperature reads distinctly warm: the reds and earth tones from Archibald Thorburn carry the compositional weight. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. #535125 functions as the palette's exclamation mark: highest chroma, lowest percentage (6.6%). The value range of 54 units sits in the comfortable middle: enough depth, enough light, neither extreme. This is palette 5 of Archibald Thorburn's sequence - a single chapter in a chromatic story told across many works.