MIKER / Graphics-ColorPicker-0.17 / examples / demo.html 
<html>
<!-- version 1.03 8-17-02 -->
<head>
<title>Color Picker</title>
<script language=javascript1.2>
var colorhex = 'none';
function pop() {
  var w;
  if (document.forms.color.what.checked){w=180;}else{w=630;}
  var colorwin = open("","colorpicker",
  "width=" + w + ",height=440,status=no,directories=no," +
  "location=no,menubar=no,scrollbars=no,toolbar=no");
  if (colorwin.opener == null) newin.opener = self;
  colorwin.document.close();
  colorwin.focus();
  return true;
}

function show() { 
  document.forms.color.hex.value = colorhex;
  alert(colorhex);
  return false;
}
</script>
<style type="text/css">
  pre {
    color: black;
    font-family: VERDANA,ARIAL,HELVETICA,SAN-SERIF;
    font-size: 12px !important;
  }
</style>
</head>
<body bgcolor="#ffffff">
<center>
<form name="color" onSubmit="return(pop());"
 action="p_gen.cgi" target="colorpicker">
<font size=2>
Enter initial color<br>
i.e. FA23DB<br></font>
<input type=text name=hex size=10>
<br>
<input type=checkbox name=what value=wo> web safe colors only
<br>
<input type=submit value="Pop Picker Window">
</form>
<a href="#top" onClick="return(show());">Show Returned VALUE</a>
<p>
<font size=+1><b>Sample Code</b></font>
</center>
<blockquote><pre>
&lt;script language=javascript1.2&gt;
// return value will be here
var colorhex = '';
var w;
function pop() {
  if (document.forms.color.what.checked){w=180;}else{w=630;}       
  var colorwin = open("","colorpicker",
  "width=" + w + ",height=440,status=no,directories=no," +
  "location=no,menubar=no,scrollbars=no,toolbar=no");
  if (colorwin.opener == null) newin.opener = self;  
  colorwin.document.close();
  colorwin.focus();
  return true;
}
&lt;/script&gt;
&lt;body&gt;
&lt;form name="color" onSubmit="return(pop());"
 action="p_gen.cgi" target="colorpicker"&gt;
&lt;input type=text name=hex size=10&gt;&lt;br&gt;
&lt;input type=checkbox name=what value=wo&gt; web safe colors only&lt;br&gt;
&lt;input type=submit value="Pop Picker Window"&gt;
&lt;/form&gt;
</pre></blockquote>
</body>
</html>