When the UseMaterial3 MSBuild property is enabled, Shell should adopt the Material 3 visual design system. However, the current implementation does not fully reflect Material 3 behavior.
Shell components such as the App Bar, TabBar, Bottom Navigation, and content background should use Material 3–specific colors, elevation rules, and surface roles, and rely on the appropriate Material 3 theme resources. Currently, some Shell elements still use Material 2 styling or static color assignments, resulting in visual inconsistencies when Material 3 is enabled.