title: LESS: Darken whatever color is already set on the element
body: <p>Just started using LESS and it's amazing. I was wondering though, is it possible to darken whatever color it was assigned.</p>
  
  <p>I have several themes on my site and when a link is active, I add it a class "active" which should darken the color and background. </p>
  
  <p>Is something like this possible:</p>
  
  <pre><code>.active{
     background:darken(10%);
  }
  </code></pre>
  
  <p>Without having to specify the background color...</p>