This is awesome! Looked at the palette definitions in draw.ts - nice that it flows through all 18 recipes from a single array. Ran the 7 palettes through deuteranopia and protanopia simulations and 4 fail (clay-sea, ember-slate, rose-forest, coral-teal), mostly where a and b have similar luminance and color information is doing all the work. The good news is that your architecture makes it a clean fix: one new entry in the PALETTES array and all 18 recipes inherit it! Are you open to PRs?