Using the bgColor property of the JavaScript window object, we can change the background color. Here is the code:

var c = new Array("00", "11", "22", "33", "44", "55",
"66", "77", "88", "99", "AA", "BB", "CC", "DD", "EE", "FF");

x = 0;

function bg_eff()
   {
   col_val = "#FFFF" + c[x];
   document.bgColor=col_val;
   x++;
   if (x == 16)
      {
      clearInterval(change_bg);
      }
   }

change_bg = setInterval("bg_eff()", 250);

The color values are stored in an array c. The function bg_eff() assigns a color value to variable col_val and then sets the bgColor property to this value. The function is called after every 250 milliseconds using the setInterval() method. On each call to the function the value of variable x is increased by one. When x equals 15, the clearInterval method() is invoked that stops the setInternval() method.