title: Slick slider change background-color for current and not current
body: <p>The colour of my slide blocks is red when is getting current and  <code>opacity: .6</code> when is not.</p>
  
  <p>What I want: when is current the background-color be red and when is not be blue.</p>
  
  <p><strong>css:</strong></p>
  
  <pre><code>body {
    background-color: grey;
  }
  
  .slick-center .slide-h3 {
    color: #FFF;
  }
  
  .slider {
    width: 600px;
    height: 150px;
    margin: 20px auto;
    text-align: center;
  }
  
  .slide-h3 {
    margin: 10% 0 10% 0;
    padding: 40% 20%;
    background: red;
  }
  
  .slider div {
    margin-right: 5px;
  }
  
  .slick-slide {
    opacity: .6;
  }
  
  .slick-center {
    display: block;
    max-width: 10% !important;
    max-height: 20% !important;
    opacity: 1;
  }
  </code></pre>
  
  <p><strong>html:</strong></p>
  
  <pre><code>&lt;h1&gt; Slick Carousel Center mode &lt;/h1&gt;
  &lt;/h1&gt;
  &lt;div class="slider"&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;1&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;2&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;3&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;4&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;5&lt;/div&gt;
    &lt;/div&gt;
    &lt;div&gt;
      &lt;div class="slide-h3"&gt;6&lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><strong>js:</strong></p>
  
  <pre><code> $(document).ready(function() {
     $('.slider').slick({
       centerMode: true,
       centerPadding: '60px',
       slidesToShow: 3,
       speed: 1500,
       index: 2,
       responsive: [{
         breakpoint: 768,
         settings: {
           arrows: false,
           centerMode: true,
           centerPadding: '40px',
           slidesToShow: 3
         }
       }, {
         breakpoint: 480,
         settings: {
           arrows: false,
           centerMode: true,
           centerPadding: '40px',
           slidesToShow: 1
         }
       }]
     });
   });
  </code></pre>
  
  <p><strong>jsfiddle:</strong>
  <a href="https://jsfiddle.net/y3xw3thy/1/" rel="nofollow">https://jsfiddle.net/y3xw3thy/1/</a></p>