you create this by using the following

<SCRIPT LANGUAGE="JAVASCRIPT">
<!--Hide the script from old browsers --
document.bgColor="red"
document.bgColor="white"
document.bgColor="blue"
document.bgColor="white"
document.bgColor="green"
document.bgColor="white"
document.bgColor="red"
document.bgColor="white"
document.bgColor="blue"
document.bgColor="white"
document.bgColor="green"
document.bgColor="white"
document.bgColor="red"
document.bgColor="white"
document.bgColor="blue"
document.bgColor="white"
document.bgColor="green"
document.bgColor="white"
 

// -- End hiding here -->
</SCRIPT>

the flickering will stop after the last color
you can change the colors any way you like