material-ui -如何在override中引用调色板？

import { createMuiTheme } from '@material-ui/core/styles';

const theme = createMuiTheme();

const theme = createMuiTheme({
  palette: {
    primary: {
      main: '#2196f3',
    },
    secondary: {
      main: '#f44336',
    },
    text: {
      primary: '#ffffff',
    },
  },
});

const styles = (theme) => ({
  root: {
    backgroundColor: theme.palette.primary.main,
    color: theme.palette.text.primary,
  },
});

const MyComponent = withStyles(styles)(({ classes }) => (
  <div className={classes.root}>Hello, Material-UI!</div>
));