To set the color of the right border in JavaScript, use the borderRightColor property. Set the color of the right border using this property.
Example
You can try to run the following code to learn how to set the color of the right border with JavaScript −
<!DOCTYPE html>
<html>
<head>
<style>
#box {
border: thick solid gray;
}
</style>
</head>
<body>
<div id="box">Demo Text</div>
<br><br>
<button type="button" onclick="display()">Change right border color</button>
<script>
function display() {
document.getElementById("box").style.borderRightColor = "green";
}
</script>
</body>
</html>