public static function hex_lighter($color, $factor = 30)
 {
     $base = WP_Email_Template_Functions::rgb_from_hex($color);
     $color = '#';
     foreach ($base as $k => $v) {
         $amount = 255 - $v;
         $amount = $amount / 100;
         $amount = round($amount * $factor);
         $new_decimal = $v + $amount;
         $new_hex_component = dechex($new_decimal);
         if (strlen($new_hex_component) < 2) {
             $new_hex_component = "0" . $new_hex_component;
         }
         $color .= $new_hex_component;
     }
     return $color;
 }