@arvindkelvin,
You can use the set method to change the color of dataseries dynamically. Please find the code-snippet below,
$(".changeColor").click(function (e) {
chart.data[0].set("color", e.target.id)
});
Also, kindly take a look at this JSFiddle for an example with complete code.

—
Adithya Menon
Team CanvasJS