<html>
<body>
<h1>HTML5 Canvas</h1>
<h2>The globalAlpha Property</h2>
<canvas id="myCanvas" width="300" height="150" style="border:1px solid grey"></canvas>
<script>
const c = document.getElementById("myCanvas");
const ctx = c.getContext("2d");
ctx.fillStyle = "red";
ctx.fillRect(20, 20, 75, 50);
// Turn transparency on
ctx.globalAlpha = 0.2;
ctx.fillStyle = "blue";
ctx.fillRect(50, 50, 75, 50);
ctx.fillStyle = "green";
ctx.fillRect(80, 80, 75, 50);
</script>
</body>
</html>