import * as React from 'react'; import { CssVarsProvider, extendTheme } from '@mui/material/styles'; import AppBar from '@mui/material/AppBar'; import Box from '@mui/material/Box'; import Paper from '@mui/material/Paper'; import Toolbar from '@mui/material/Toolbar'; const theme = extendTheme({ colorSchemes: { dark: true }, colorSchemeSelector: '.mode-%s' }); export default function MaterialUIDefaultDark() { const [, rerender] = React.useState(false); React.useEffect(() => { // Trigger rerender to ensure that the UI does not change after the first render. // To catch bug like https://github.com/mui/material-ui/issues/36452 rerender(true); }, []); return ( div': { placeSelf: 'center', }, }} > The color should be `palette.AppBar.darkBg` You should see overlay. ); }