<html>
<head>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3@7"></script>
</head>
<body>
<h3>Simple transitions</h3>
<script>
d3.selectAll("h3").transition().style("color", "rgb(0,150,120)").duration(5000);
</script>
</body>
</html>