:active

The :active CSS pseudo-class matches when an element is being activated by the user. It allows the page to give a feedback that the activation has been detected by the browser. When interacting with a mouse, this is typically the time between the user presses the mouse button and releases it. The :active pseudo-class is also typically matched when using the keyboard tab key. It is frequently used on <a> and <button> HTML elements, but may not be limited to just those.
 
This style may be overridden by any other link-related pseudo-classes, that is :link, :hover, and :visited, appearing in subsequent rules. In order to style appropriately links, you need to put the :active rule after the all others link-related rules, as defined by the LVHA-order: :link — :visited — :hover — :active.

<!DOCTYPE html>
<html>
    <head>
        <style> 
            a:active {
                color: #0F3
            }
             /* active links */ 
        </style>
    </head>
    <body>
        <body>
            <p>
                Click this link to see active effect
				<a href="#">will change on click</a>
            </p>
        </body>
    </body>
</html>