Check out the WordPress Plugin of lightGallery

Lightgallery custom events

This is just a demonstration of how to use custom events. You can find more custom events here. In this demo you will see background color of gallery changes on every slide

HTML structure

<div id="custom-events">
  <a href="img/img1.jpg">
      <img src="img/thumb1.jpg" />
  </a>
  <a href="img/img2.jpg">
      <img src="img/thumb2.jpg" />
  </a>
  ...
</div>

Javascript

var $customEvents = $('#custom-events');
$customEvents.lightGallery();

var colours = ['#21171A', '#81575E', '#9C5043', '#8F655D'];
$customEvents.on('onBeforeSlide.lg', function(event, prevIndex, index){
    $('.lg-outer').css('background-color', colours[index])
});

Css (for background color transition)

.lg-outer{
    transition: background-color 600ms ease 0s;
}