Get prefers color scheme by pure JavaScript

prefers-color-scheme.js

// Get instant color scheme
window.matchMedia( '(prefers-color-scheme: dark)' ).addEventListener( 'change', e => {
    
    let mode = e.matches ? "dark" : "light";

    if ( mode == "dark" ){
        console.log('Now Dark');
    }else{
        console.log('Now Light');
    }
    
} );

// Get current color scheme
if ( window.matchMedia && window.matchMedia( '(prefers-color-scheme: dark)' ).matches ) {
    
    console.log( 'Hello Dark' );
    
} else {
    
    console.log( 'Hello Light' );
    
}