<html>
<head>
<script>
// (C) 2000 by CodeLifter.com
// http://www.codelifter.com
// Free for all users, but leave in this header
// blink speed in miliseconds
var rate = 333;
// true to start automatically, else false
var DoIt = true
// the three blink colors
var Color1 = "#FF0000"
var Color2 = "#00FF00"
var Color3 = "#0000FF"
// the color if/when turned off
var ColorX = "#C0C0C0"
var i = 0;
function doTriStateRainbow(){
 if (document.all){
 if (DoIt){
 i++;
 if (i==1) C = Color1
 if (i==2) C = Color2
 if (i==3) C = Color3
 document.body.style.scrollbarBaseColor = C
 if (i>2) i=0;
 timer=setTimeout('doTriStateRainbow()', rate)
 }else{
 document.body.style.scrollbarBaseColor = ColorX
 }
 }
}
</script></head>
<body onload="doTriStateRainbow()">
Blinkende Scroll-Leiste aus und an schalten 
<a href="#" onClick="DoIt=false">AUS</a> / <a href="#" onClick="DoIt=true;doTriStateRainbow()">AN</a>
 
</body></html>

Blinkende Scroll-Leiste aus und an schalten AUS / AN