var hexChars = "0123456789ABCDEF";

function Dec2Hex (Dec)
  { var a = Dec % 16;
    var b = (Dec - a)/16;
    hex = "" + hexChars.charAt(b) + hexChars.charAt(a);
    return hex;
  }

function bgChanger (begin, end, steps)
  { steps = steps -1 ;
    redA     = begin.charAt(0) + begin.charAt(1);
    red_valA = parseInt(redA,'16');
    redB     = end.charAt(0) + end.charAt(1);
    red_valB = parseInt(redB,'16');
    red_int  = ((red_valB - red_valA) / steps) * -1;
    grnA     = begin.charAt(2) + begin.charAt(3);
    grn_valA = parseInt(grnA,'16');
    grnB     = end.charAt(2) + end.charAt(3);
    grn_valB = parseInt(grnB,'16');
    grn_int  = ((grn_valB - grn_valA) / steps) * -1;
    bluA     = begin.charAt(4) + begin.charAt(5);
    blu_valA = parseInt(bluA,'16');
    bluB     = end.charAt(4) + end.charAt(5);
    blu_valB = parseInt(bluB,'16');
    blu_int  = ((blu_valB - blu_valA) / steps) * -1;
    step = 2;
    red = red_valA;
    grn = grn_valA;
    blu = blu_valA;
    document.bgColor = begin;
    while ( steps >= step )
      { red -= red_int;
        red_round = Math.round(red);
        red_hex = Dec2Hex(red);
        grn -= grn_int;
        grn_round = Math.round(grn);
        grn_hex = Dec2Hex(grn);
        blu -= blu_int;
        blu_round = Math.round(blu);
        blu_hex = Dec2Hex(blu);
        document.bgColor = red_hex + grn_hex + blu_hex;
        step++;
      }
    document.bgColor = end;
  }

// blue to blue (pause)
bgChanger("0066FF","0066FF",25);

// blue to red
bgChanger("0066FF","FF0000",25);

// red to blue
bgChanger("FF0000","0066FF",25);

// blue to lime
bgChanger("0066FF","00FF00",25);

// lime to blue
bgChanger("00FF00","0066FF",25);

// blue to yellow
bgChanger("0066FF","FFFF00",25);

// yellow to blue
bgChanger("FFFF00","0066FF",25);

// blue to red
bgChanger("0066FF","FF0000",25);

// red to blue
bgChanger("FF0000","0066FF",25);

// blue to lime
bgChanger("0066FF","00FF00",25);

// lime to blue
bgChanger("00FF00","0066FF",25);

// blue to yellow
bgChanger("0066FF","FFFF00",25);

// yellow to blue
bgChanger("FFFF00","0066FF",25);

// blue to blue (pause)
bgChanger("0066FF","0066FF",25);