This code should do it:

******************************************
<html>
<head>
<title>changing colors</title>

<style TYPE = "text/css">

p {color:black;}

</style>

<script LANGUAGE = "JavaScript">

function changeMe(){

var numTags = 0;

numTags = document.all.tags("p").length;

for( var i = 0; i < numTags; i++){

document.all.tags("P")[i].style.color = 'blue';
}

}//end function

</script>

</head>
<body>

<p ONCLICK = "changeMe();">
<br>
<b> Text within the p tags</b>
<br>
</p>
<p>Second p tag</p>
</body>
</html>
********************************************

Chris