WordPress staging site admin bar indicator — orange background + staging label

functions.php

// Enqueue custom CSS for the admin bar if on a staging site
function eevolve_custom_admin_bar_css() {
	if ( strpos( get_site_url(), 'staging' ) !== false ) {
		wp_register_style( 'eevolve-admin-bar-css', false );
		wp_enqueue_style( 'eevolve-admin-bar-css' );
		wp_add_inline_style(
			'eevolve-admin-bar-css',
			'
            #wpadminbar { background-color: #cc8400; }
            #wp-admin-bar-woocommerce-site-visibility-badge { display: none; }
        '
		);
	}
}
add_action( 'admin_enqueue_scripts', 'eevolve_custom_admin_bar_css' );
add_action( 'wp_enqueue_scripts', 'eevolve_custom_admin_bar_css' );

// Add "Staging" label to the admin bar
function eevolve_add_staging_label( $wp_admin_bar ) {
	if ( strpos( get_site_url(), 'staging' ) !== false ) {
		$wp_admin_bar->add_node(
			array(
				'id'    => 'staging_label',
				'title' => 'Reminder: This is the Staging Site',
				'href'  => '#',
				'meta'  => array(
					'title' => 'This is a staging site',
					'class' => 'staging-label',
				),
			)
		);
	}
}
add_action( 'admin_bar_menu', 'eevolve_add_staging_label', 999 );