Low-key values are the structural spine of Otto Bache, giving it gravity and atmosphere. Temperature reads distinctly warm: the reds and earth tones from Otto Bache carry the compositional weight. Every colour is desaturated; the palette proceeds through near-neutrals and gently-coloured greys. The highest-chroma note - #764D30 - appears at just 6.6%, deployed as a precision accent against the quieter ground. A value spread of 58 units gives the palette both depth and air - shadows are genuinely dark, lights genuinely light. Together these qualities place Otto Bache firmly in the tonal tradition - concerned with mood and atmosphere rather than chromatic display. In the context of Otto Bache's full range of palettes, group 4 represents one movement in an ongoing chromatic dialogue.