title: change button color Lightbox
body: <p>I'm using classic Galleria theme. I implemented the lightbox and changed the frame color:</p>
  
  <pre><code>.galleria-lightbox-shadow{background-color: transparent !important}
  .galleria-lightbox-content{background:black !important}
  </code></pre>
  
  <p>But is it possible to change the color of the next, previous and close buttons in Lightbox?</p>
  
  <p>Right now they are white. I would like to have them in black. Is there a solution to that?</p>