To implement:

Calculate difference between old and new RGB values

  

<html>
<head>
<title></title>
<script language="JavaScript">
<!-- Start Script


// calculate the difference btw new and old RGB values
// Analysis

var newRed = 255;
var oldRed = 0;
var newGreen = 0;
var oldGreen = 0;
var oldBlue = 255;
var newBlue = 155;

var difRed = newRed - oldRed;
var difGreen = newGreen - oldGreen;
var difBlue = newBlue - oldBlue;

document.writeln("oldRed: " + oldRed + "<br>newRed: " + newRed);
document.writeln("<br>difRed: " + difRed);
document.writeln("<p>oldGreen: " + oldGreen + "<br>newGreen: " + newGreen);
document.writeln("<br>difGreen: " + difGreen);
document.writeln("<p>oldBlue: " + oldBlue + "<br>newBlue: " + newBlue);
document.writeln("<br>difBlue: " + difBlue);

// End Script -->
</script>
</head>
<body>
</body>
</html>

 

Execute code or main page