<html>
<head>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3@7"></script>
</head>
<body>
<h3>Simple transitions</h3>
<script>
d3.select("body").transition().duration(2000).style("background-color", "red") // make the background-color
lightblue.transition()
.transition().duration(1000).style("background-color", "green"); // make the background-color gray
</script>
</body>
</html>