To set the outline color, use the outlineColor property. You can try to run the following code to set the color of the outline around an element with JavaScript:
Example
<!DOCTYPE html> <html> <head> <style> #box { width: 450px; background-color: orange; border: 3px solid red; } </style> </head> <body> <p>Click below to add Outline Color.</p> <div id="box"> <p>This is a div. This is a div. This is a div. This is a div. This is a div.</p> <p>This is a div. This is a div. This is a div. This is a div. This is a div.</p> <p>This is a div. This is a div. This is a div. This is a div. This is a div.</p> </div> <br> <button type="button" onclick="display()">Set Outline Color</button> <br> <script> function display() { document.getElementById("box").style.outline = "thick solid"; document.getElementById("box").style.outlineColor = "#5F5F5F"; } </script> </body> </html>