Zed launches Theme Builder, a visual editor for creating custom editor themes without editing JSON. The tool features live preview, an inspector to identify which tokens control specific UI elements, color linking to maintain consistency across related elements, and Tree-sitter-powered syntax highlighting that matches Zed exactly. Users can import existing themes, make changes with instant visual feedback, and export as theme overrides or extensions. The interface uses CSS custom properties for instant updates and includes undo/redo support with local storage persistence.