Cameron's art verdict after the material-render landing: the world renders in solid-color flat materials under light — palette from one named table, emissive as information, shader-level functional detail, no image textures. Constitution visual-identity refinement + decisions entry (rejected alternatives recorded: AI texture tooling, licensed packs, commissioned tilesets — the last reserved for a possible hero pass). New spec wiki/interface/flat-materials.md (READY, 7 criteria); ROADMAP #13 (Pixel Lab regeneration) retired, #29 added; pixel-pipeline.md carries the retirement note. Docs only; the amendment precedes the implementation (#29). Defense: 'Visual identity: clinical gore' already assigns the detail budget to function over noise, and 'Justification and legibility' wants every visible thing informational; the material-render evidence showed lighting and palette carrying the identity while textures fought it. The refinement makes the renderer serve the decided identity with less machinery, not a new identity.