One palette serves both layers — the [layer] rule

A preset that composes a second scene ([layer], see presets/README.md) has no [layer.palette], deliberately: the preset’s single [palette] (and [palette_b] pair) is baked once and handed to the main scene, the layer’s scene and the backdrop alike. Two colour languages in one frame read as two presets stacked rather than one world, and a second bake would double the LUT work for a coherence loss, not a gain — the shared gradient is precisely what makes two layers one look. The omission is deliberate (ADR-0090).

What still differs per layer is how each scene samples that shared gradient: the layer has its own hue, saturation, color_span / hue_spread, palette_mix and friends in [layer.params], so the two layers can sit at different points of one gradient — a dim ground at the palette’s floor under a bright figure at its crest — without leaving the family.

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