Javascript 
Background Effects Disco Background Animation
Background Effects Disco Background Animation Background Effects Disco Background Animation In this tutorial you will discover a very nice background animation. It's about change color of the background!
<script language="JavaScript">
<!--
//you can assign the initial color of the background here
r=255;
g=255;
b=255;
flag=0;
t=new Array;
o=new Array;
d=new Array;
function hex(a,c)
{
t[a]=Math.floor(c/16)
o[a]=c%16
switch (t[a])
{
case 10:
t[a]='A';
break;
case 11:
t[a]='B';
break;
case 12:
t[a]='C';
break;
case 13:
t[a]='D';
break;
case 14:
t[a]='E';
break;
case 15:
t[a]='F';
break;
default:
break;
}
switch (o[a])
{
case 10:
o[a]='A';
break;
case 11:
o[a]='B';
break;
case 12:
o[a]='C';
break;
case 13:
o[a]='D';
break;
case 14:
o[a]='E';
break;
case 15:
o[a]='F';
break;
default:
break;
}
}
function ran(a,c)
{
if ((Math.random()>2/3||c==0)&&c<255)
{
c++
d[a]=2;
}
else
{
if ((Math.random()<=1/2||c==255)&&c>0)
{
c--
d[a]=1;
}
else d[a]=0;
}
return c
}
function do_it(a,c)
{
if ((d[a]==2&&c<255)||c==0)
{
c++
d[a]=2
}
else
if ((d[a]==1&&c>0)||c==255)
{
c--;
d[a]=1;
}
if (a==3)
{
if (d[1]==0&&d[2]==0&&d[3]==0)
flag=1
}
return c
}
function disco()
{
if (flag==0)
{
r=ran(1, r);
g=ran(2, g);
b=ran(3, b);
hex(1,r)
hex(2,g)
hex(3,b)
document.body.style.background="#"+t[1]+o[1]+t[2]+o[2]+t[3]+o[3]
flag=50
}
else
{
r=do_it(1, r)
g=do_it(2,g)
b=do_it(3,b)
hex(1,r)
hex(2,g)
hex(3,b)
document.body.style.background="#"+t[1]+o[1]+t[2]+o[2]+t[3]+o[3]
flag--
}
setTimeout('disco()',50)
}
//-->
</script>
<body onload="disco()">
This script has been developed by http://www.javascriptkit.com !
