Every stroke carries a REAL PIGMENT MIXTURE: the enabled paints are
premixed (pairs at quantized ratios + white/black ladders) through Kubelka–Munk optics
— K (absorption) and S (scattering) per channel, masstone reflectance
R∞ = 1 + K/S − √((K/S)² + 2K/S) — and each stroke snaps to the nearest pile in Oklab.
Blue+yellow makes green, black+yellow makes olive, because the physics says so.
Pigment K/S data: Curtis et al., “Computer-Generated Watercolor”, SIGGRAPH ’97, fig. 5.
Keys: ` final, 1–4 views (press again to return), hold X = photo,
hold W = block-in, Z fit/100%, wheel zoom, Space-drag pan,
O open, D download. Brushes: drag to paint, Alt erases,
[ ] size, Ctrl/⌘Z undo, Ctrl+Y/⌘⇧Z redo.
The paint store
Your palette — click a tube to put it back on the shelf:
3–6 tubes plus a white and a black is a
painter's kit — the palette IS the look. Each swatch: masstone → tint with white.