Low-key values are the structural spine of Rachel Ruysch, giving it gravity and atmosphere. Rachel Ruysch builds on cool foundations: the palette favours the blue-cyan-green arc. Chroma hovers near zero; colour declares itself through subtle shifts in hue rather than outright saturation. #05040E at 62.6% of the palette: an overwhelming presence that pulls all other colours into its gravitational field. The most saturated colour, #73291D, is reserved to 1.5% of the surface, where it acts as a focal punctuation. The value range of 52 units sits in the comfortable middle: enough depth, enough light, neither extreme. Together these qualities place Rachel Ruysch firmly in the tonal tradition - concerned with mood and atmosphere rather than chromatic display. This is palette 6 of Rachel Ruysch's sequence - a single chapter in a chromatic story told across many works.