function hex2rgb(hex) {
  if (hex[0]=="#") hex=hex.substr(1);
  if (hex.length==3) {
    var temp=hex; hex='';
    temp = /^([a-f0-9])([a-f0-9])([a-f0-9])$/i.exec(temp).slice(1);
    for (var i=0;i<3;i++) hex+=temp[i]+temp[i];
  }
  var triplets = /^([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})$/i.exec(hex).slice(1);
  return {
    red:   parseInt(triplets[0],16),
    green: parseInt(triplets[1],16),
    blue:  parseInt(triplets[2],16)
  }
}

// Example
var hex = "#fA0";
var rgb = hex2rgb(hex);
document.write("<pre>"+hex+" \u2192 rgb("+rgb.red+","+rgb.green+","+rgb.blue+")</pre>");

http://sverri.tumblr.com/post/865857181/javascript-hex-to-rgb-converter

Converts and returns the RGB equivalent of a HEX value. The RGB values are returned as an object, with the members "red", "green" and "blue". See the example in code snippet if you do not know how to use the function.

HEX to RGB Converter

JavaScript