Palettes

Every palette in midi-sink is the same small object: stops of linear RGB along the depth axis — the ink’s thickness in Sumi, the charge’s glow in Anod — a depth curve that says how the depth walks the ramp, a hue drift by which each drop leans toward an accent colour of its own, and the tone of the clear water between the rings. The composite reads nothing else. The medium’s three built-in palettes are that object too — sumi black, indigo and ochre; electric blue, plasma orange and phosphor green — two-stop palettes of one colour drifting toward their accent, and they print bitwise as they did before the model existed.

The identity guardrail. A palette chooses hues. It does not touch the washi’s soak, the pooled ink’s near-black, or the way strain lights a charge: those are the medium’s, and the same for every palette. The curated library is the identity statement; the editor is freedom within it.

The library. Beside the built-ins, presets considerate of colour-blind players: Cobalt & amber — the Okabe–Ito blue and orange, safe under deuteranopia and protanopia — as ink and drift or as charge and halo, and the perceptual ramps Viridis and Cividis, thin ink bright to pooled ink dark, dim charge violet to burning charge yellow. Loading one fills the custom slot as a starting point.

The ring. A palette-morph control travels the ring from the active palette — built-in to built-in as always; from the custom slot, through the three built-ins and back.

The editor

On every platform the Palette page holds the active choice (the three built-ins and Custom), the library with Load into custom, and the custom slot’s editor: the stops (add, remove, each with its position and colour), Depth curve (below 1 the ink pools early, above 1 late), Depth floor, Hue drift and Drift toward (the accent — the halo under Anod), Clear water. A session preset carries the custom slot.

Invariants

• Bitwise. The canonical script printed under every built-in of both media, at rest and under morph, hashes as it did through the old tables.
• One path. The composite has no palette table; a built-in, a preset and the custom slot are the same bytes read the same way.
• Round trip. Every preset set through the core comes back byte-equal.

Ownership

• sumi_palette_t (2–8 stops, depth_gamma, depth_floor, hue_drift, accent_rgb, clear_rgb), sumi_set_palette / sumi_get_palette; active_palette_id 0–2 the built-ins, 3 the custom slot; sumi_palette_preset_count / sumi_palette_preset the library; the Palette morph CC dimension the ring.