Background applied to the currently-active nav item. Falls back to a low-opacity primary overlay.
Color of group-header text. Falls back to theme.palette.text.secondary.
Background on hover. Falls back to theme.palette.action.hover.
Sidebar background (desktop) and mobile drawer content. Falls back to theme.palette.background.paper.
Right-edge border on the desktop sidebar. Falls back to theme.palette.divider.
Colors for PortalLayout. Each value falls back to a standard MUI theme token when left as an empty string (the default).