title: Twitter Bootstrap - How to get the grey glyphicon
body: <p>I am using twitter bootstrap and I have a question on the glyphicon used in their home page. For reference, take the Base CSS page: <a href="http://twitter.github.com/bootstrap/base-css.html" rel="noreferrer">http://twitter.github.com/bootstrap/base-css.html</a>  </p>
  
  <p>On the left side, you can see the Navigation - Typography, Code, Tables and the like. Now if you notice, the navigation contains the glyphicon identified by the class "icon-chevron-right". However, the icon is not black or white. It is grey. When the mouse hovers over a particular item, the icon turns into a darker shade of grey. The CSS does not show anything out of the ordinary and seems to refer the black glyphicon, yet the icon is grey and has a hover effect.  </p>
  
  <p>Any idea which feature of bootstrap is being used here?</p>