Edit in JSFiddle

// Visualize: Basic Customization  (5.6)

// This Fiddle usesd a non-standard demo report:
//    /public/viz/Hyperlinks/Drill_Reports_with_Controls/main_report

visualize({
    auth: {
        name: "jasperadmin",
        password: "jasperadmin",
        organization: "organization_1"
    }
},function (v) {
    v("#container1").report({
        resource: "/public/viz/Hyperlinks/Drill_Reports_with_Controls/main_report",
        linkOptions: {
            beforeRender: function (linkToElemPairs) {
                linkToElemPairs.forEach(function (pair) {
                    var el = pair.element;
                    el.style.backgroundColor = "red";
                });
            },
            events: {
                "click": function(ev, link){
                    if (confirm("Change color of link id " + link.id + " to green?")){
                        ev.currentTarget.style.backgroundColor = "green";
                        ev.target.style.color = "#FF0";
                    }
                }
            }    
        },
        error: function (err) {
            alert(err.message);
        }
    });
});

<!-- Visualize: Basic Customization  (5.6)
  -->

<!--Provide URL to visualize.js-->
<script src="http://visualizejs-preview.eng.jaspersoft.com:8080/jasperserver-pro-branch/client/visualize.js"></script>
<!--Provide container to render your visualization-->
<div id="container1"></div>