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CSS theme variables - Usage

Learn how to adopt CSS theme variables.

Getting started

The CSS variables API relies on a provider called CssVarsProvider to inject styles into Material UI components. CssVarsProvider generates CSS variables out of all tokens in the theme that are serializable, and makes them available in the React context along with the theme itself via ThemeProvider.

Once the App renders on the screen, you will see the CSS theme variables in the HTML :root stylesheet. The variables are flattened and prefixed with --mui by default:

/* generated global stylesheet */
:root {
  --mui-palette-primary-main: #1976d2;
  --mui-palette-primary-light: #42a5f5;
  --mui-palette-primary-dark: #1565c0;
  --mui-palette-primary-contrastText: #fff;
  /* ...other variables */

The following demo uses --md-demo as a prefix for the variables:

Press Enter to start editing

Toggle between light and dark mode

The useColorScheme hook lets you read and update the user-selected mode:

import { CssVarsProvider, useColorScheme } from '@mui/material/styles';

// ModeSwitcher is an example interface for toggling between modes.
// Material UI does not provide the toggle interface—you have to build it yourself.
const ModeSwitcher = () => {
  const { mode, setMode } = useColorScheme();
  const [mounted, setMounted] = React.useState(false);

  React.useEffect(() => {
  }, []);

  if (!mounted) {
    // for server-side rendering
    // learn more at
    return null;

  return (
      onClick={() => {
        if (mode === 'light') {
        } else {
      {mode === 'light' ? 'Dark' : 'Light'}

function App() {
  return (
      <ModeSwitcher />

Using theme variables

All of these variables are accessible in an object in the theme called vars. The structure of this object is nearly identical to the theme structure, the only difference is that the values represent CSS variables.

  • theme.vars (recommended): an object that refers to the CSS theme variables.

    const Button = styled('button')(({ theme }) => ({
      backgroundColor: theme.vars.palette.primary.main, // var(--mui-palette-primary-main)
      color: theme.vars.palette.primary.contrastText, // var(--mui-palette-primary-contrastText)

    For TypeScript, the typings are not enabled by default. Follow the TypeScript setup to enable the typings.

  • Native CSS: if you can't access the theme object, for example in a pure CSS file, you can use var() directly:

    /* external-scope.css */
    .external-section {
      background-color: var(--mui-palette-grey-50);

Server-side rendering

Place <InitColorSchemeScript /> before the <Main /> tag to prevent the dark-mode SSR flickering during the hydration phase.

Next.js App Router

Add the following code to the root layout file:

import InitColorSchemeScript from '@mui/material/InitColorSchemeScript';

export default function RootLayout({ children }) {
  return (
    <html lang="en">
        <InitColorSchemeScript /> {/* must come before the <main> element */}

Next.js Pages Router

Add the following code to the custom pages/_document.js file:

import Document, { Html, Head, Main, NextScript } from 'next/document';
import InitColorSchemeScript from '@mui/material/InitColorSchemeScript';

export default class MyDocument extends Document {
  render() {
    return (
      <Html data-color-scheme="light">
          <InitColorSchemeScript /> {/* must come before the <Main> element */}
          <Main />
          <NextScript />


The theme variables type is not enabled by default. You need to import the module augmentation to enable the typings:

// The import can be in any file that is included in your `tsconfig.json`
import type {} from '@mui/material/themeCssVarsAugmentation';
import { styled } from '@mui/material/styles';

const StyledComponent = styled('button')(({ theme }) => ({
  // ✅ typed-safe
  color: theme.vars.palette.primary.main,


<CssVarsProvider>  props

  • defaultMode?: 'light' | 'dark' | 'system' - Application's default mode (light by default)
  • disableTransitionOnChange : boolean - Disable CSS transitions when switching between modes
  • theme: ThemeInput - the theme provided to React's context
  • modeStorageKey?: string - localStorage key used to store application mode
  • attribute?: string - DOM attribute for applying color scheme

useColorScheme: () => ColorSchemeContextValue

  • mode: string - The user's selected mode
  • setMode: mode => {…} - Function for setting the mode. The mode is saved to internal state and local storage; if mode is null, it will be reset to the default mode

<InitColorSchemeScript>  props

  • defaultMode?: 'light' | 'dark' | 'system': - Application's default mode before React renders the tree (light by default)
  • modeStorageKey?: string: - localStorage key used to store application mode
  • attribute?: string - DOM attribute for applying color scheme
  • nonce?: string - Optional nonce passed to the injected script tag, used to allow-list the next-themes script in your CSP