Joan Blaeu is high-key - luminous, open, and weighted toward light. Temperature is cool-dominant, with blue and green families claiming the largest areas. Chroma is kept low across all colours, producing the soft, enveloping quality that characterises tonal painting. A single dominant - #CEC6B5 at 35.7% - sets the character of the whole composition. The most saturated colour, #CAAF7A, is reserved to 3.8% of the surface, where it acts as a focal punctuation. The full value range is 61 units: broad enough to build convincing three-dimensional form. The palette has the character of outdoor light: cool, mid-bright, with colour rendered faithfully rather than expressively. This is palette 1 of Joan Blaeu's sequence - a single chapter in a chromatic story told across many works.