To implement:

Write function to calculate the total number of steps and individual increment amounts between two colours.

 

<html>
<head>
<title></title>
<script language="JavaScript">
<!-- Start Script
// calculate # of increment steps and individual increments
// Analysis

var min = "blue";
var difRed = -200;
var difGreen = 0;
var difBlue = 100;

// min is red -> calculate relative green and blue steps
// Analysis
if(min == "red")
	{
	steps = Math.abs(difRed);
	if(difRed > 0)
		Rsteps = 1;
	else
		Rsteps = -1;
	Gsteps = difGreen / Math.abs(difRed);
	Bsteps = difBlue / Math.abs(difRed);
	}

// min is green -> calculate relative red and blue steps
// Analysis
else if(min == "green")
	{
	steps = Math.abs(difGreen);
	Rsteps = difRed / Math.abs(difGreen);
	if(difGreen > 0)
		Gsteps = 1;
	else
		Gsteps = -1;
	Bsteps = difBlue / Math.abs(difGreen);
	}
// min is blue -> calculate relative red and green steps
// Analysis
else 
	{
	steps = Math.abs(difBlue);
	Rsteps = difRed / Math.abs(difBlue);
	Gsteps = difGreen / Math.abs(difBlue);
	if(difBlue > 0)
		Bsteps = 1;
	else
		Bsteps = -1;
	}

// show results
// Analysis
document.writeln("min: " + min + "<br>");
document.writeln("difRed: " + difRed + "<br>");
document.writeln("difGreen: " + difGreen + "<br>");
document.writeln("difBlue: " + difBlue + "<p>");
document.writeln("steps: " + steps + "<br>");
document.writeln("Rsteps: " + Rsteps + "<br>");
document.writeln("Gsteps: " + Gsteps + "<br>");
document.writeln("Bsteps: " + Bsteps + "<p>");

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

 

Execute code or main page