React Native useColorScheme

Summary: in this tutorial, you will learn how to use the useColorScheme hook to get the current user-preferred color scheme.

Introduction to the React Native useColorScheme hook

The useColorScheme hook allows you to get the current user-preferred color scheme.

First, import the useColorScheme hook from the react-native library:

import {useColorScheme} from 'react-native';Code language: JavaScript (javascript)

Then, use the useColorScheme in your functional component to get the current user-preferred color scheme:

const colorScheme = useColorScheme();Code language: JavaScript (javascript)

The useColorScheme() hook returns a string or null that indicates the current color scheme. It can be one of three values:

• 'light': light color scheme.
• 'dark': dark color scheme.
• null: no color scheme has been chosen by the user.

The following example shows how to use the useColorScheme hook to switch between dark and light themes:

import {useState} from 'react';
import { Text, SafeAreaView, StyleSheet, Switch, useColorScheme } from 'react-native';

export default function App() {
  
  const colorScheme = useColorScheme();

  const [isDarkMode, setIsDarkMode] = useState(colorScheme === 'dark');

  const theme = isDarkMode ? styles.darkTheme : styles.lightTheme;

  return (
    <SafeAreaView style={[styles.container, theme.background]}>
      <Text style={[styles.text, theme.text]}>JavaScriptTutorial.Net</Text>
      <Switch
        trackColor={{ false: "#767577", true: "#81b0ff" }}
        thumbColor={isDarkMode ? "#f5dd4b" : "#f4f3f4"}
        ios_backgroundColor="#3e3e3e"
        onValueChange={() => setIsDarkMode(!isDarkMode)}
        value={isDarkMode}
      />
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
  text: {
    fontSize: 20,
    marginBottom: 20,
  },
  lightTheme: {
    background: {
      backgroundColor: '#fff',
    },
    text: {
      color: '#000',
    },
  },
  darkTheme: {
    background: {
      backgroundColor: '#000',
    },
    text: {
      color: '#fff',
    },
  },
});Code language: JavaScript (javascript)

Output:

How it works.

First, call the useColorTheme hook inside the App component:

const colorScheme = useColorScheme();Code language: JavaScript (javascript)

Second, create a state variable to store a value indicating if the current theme is dark. It defaults to the user-preferred theme:

const [isDarkMode, setIsDarkMode] = useState(colorScheme === 'dark');Code language: JavaScript (javascript)

Third, assign a style property (dark theme or light theme) to the theme variable based on the value of the isDarkMode state:L

const theme = isDarkMode ? styles.darkTheme : styles.lightTheme;Code language: JavaScript (javascript)

Fourth, use the text and background styles in the components based on whether the theme is dark or light. Additionally, create a Switch component to switch between the dark and light theme.

<SafeAreaView style={[styles.container, theme.background]}>
    <Text style={[styles.text, theme.text]}>JavaScript Tutorial</Text>
    <Switch
        trackColor={{ false: "#767577", true: "#81b0ff" }}
        thumbColor={isDarkMode ? "#f5dd4b" : "#f4f3f4"}
        ios_backgroundColor="#3e3e3e"
        onValueChange={() => setIsDarkMode(!isDarkMode)}
        value={isDarkMode}
    />
</SafeAreaView>Code language: JavaScript (javascript)

Finally, define the styles with the dark and light themes:

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
  text: {
    fontSize: 20,
    marginBottom: 20,
  },
  lightTheme: {
    background: {
      backgroundColor: '#fff',
    },
    text: {
      color: '#000',
    },
  },
  darkTheme: {
    background: {
      backgroundColor: '#000',
    },
    text: {
      color: '#fff',
    },
  },
});Code language: JavaScript (javascript)

Summary

• Use the React Native useColorScheme hook to get the current user-preferred color theme.