<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<style>
html, body {
margin: 0;
}
</style>
<body>
<canvas id="dest" height="100" width="100"></canvas>
<script type="text/javascript">
var destCanvas = document.getElementById('dest');
var destCtx = destCanvas.getContext('2d');
destCtx.fillStyle = "#FF0000";
destCtx.fillRect(0, 0, destCanvas.width, destCanvas.height);
</script>
</body>
</html>