title: RGBa in Internet Explorer
body: <p>I know that IE does not support RGBa. I also know that you can use the follow methods:</p>
  
  <pre><code>/* For IE 5.5 - 7*/
  filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000);
  /* For IE 8*/
  -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)";
  </code></pre>
  
  <p>The first two Numbers in the "Colorstr" is the value for the opacity. with 99 being a .6 opacity.  For other levels of opacity what are the number values? I cannot find them. Is there a simple way to calculate the number for opacity? Or where can I find those values?  </p>
  
  <p>Thanks => </p>