Code
<p id="a">
ЗДЕСЬ ПИШЕМ ТЕКСТ</p>
<script language="JavaScript" type="text/javascript">
function change()
{
re="rgb("+Math.round(Math.random()*256)+","+Math.round(Math.random()*256)+","+Math.round(Math.random()*256)+")"
a.style.color= re;
}
setInterval(change,1000);
</script>