File: //usr/share/doc/libjs-excanvas/examples/testcases/gradient.html
<!DOCTYPE html>
<html>
<head>
<title>Gradient Test</title>
<style>
body {
text-align: center
}
</style>
<!--[if IE]><script type="text/javascript" src="../excanvas.js"></script><![endif]-->
<script>
window.onload = function() {
var ctx = document.getElementById('c').getContext('2d');
var g = ctx.createLinearGradient(0, 0, 300, 0);
g.addColorStop(0, '#000');
g.addColorStop(1 / 7, '#00f');
g.addColorStop(2 / 7, '#0f0');
g.addColorStop(3 / 7, '#0ff');
g.addColorStop(4 / 7, '#f00');
g.addColorStop(5 / 7, '#f0f');
g.addColorStop(6 / 7, '#ff0');
g.addColorStop(1, '#fff');
ctx.fillStyle = g;
ctx.fillRect(0, 0, 300, 200);
};
</script>
</head>
<body>
<canvas id=c width=300 height=200></canvas>
<p>This tests gradients</p>
</body>
</html>