gistfile1.php

<?php
function add_styles_scripts(){
    //Access the global $wp_version variable to see which version of WordPress is installed.
    global $wp_version;
    
    //If the WordPress version is greater than or equal to 3.5, then load the new WordPress color picker.
    if ( 3.5 <= $wp_version ){
      //Both the necessary css and javascript have been registered already by WordPress, so all we have to do is load them with their handle.
      wp_enqueue_style( 'wp-color-picker' );
      wp_enqueue_script( 'wp-color-picker' );
    }
    //If the WordPress version is less than 3.5 load the older farbtasic color picker.
    else {
      //As with wp-color-picker the necessary css and javascript have been registered already by WordPress, so all we have to do is load them with their handle.
      wp_enqueue_style( 'farbtastic' );
      wp_enqueue_script( 'farbtastic' );
    }
    
    //Load our custom javascript file
    wp_enqueue_script( 'wp-color-picker-settings', plugin_dir_url( __FILE__ ) . 'js/settings.js' );
  }
?>