Changing the color on a Link Template


I’m trying create a context menu to change the color of a Link this is what I got so far, I’m not sure how to get the color part of the link

function changeColor(e, obj) {
            myDiagram.commit(function(d) {
              // get the context menu that holds the button that was clicked
                var contextmenu = obj.part;
                var linkdata =;
              // compute the next color for the node
              //var newcolor = "lightblue";
              //switch (nodedata.color) {
              //  case "lightblue": newcolor = "lightgreen"; break;
              //  case "lightgreen": newcolor = "lightyellow"; break;
              //  case "lightyellow": newcolor = "orange"; break;
              //  case "orange": newcolor = "lightblue"; break;
              //// modify the node data
              //// this evaluates data Bindings and records changes in the UndoManager
              //d.model.set(nodedata, "color", newcolor);
            }, "changed color");

        //Link Template
        myDiagram.linkTemplate = $$(go.Link, {
                layerName: "Background",
                routing: go.Link.AvoidsNodes,
                corner: 15,
                curve: go.Link.JumpGap,
                reshapable: true,
                resegmentable: true,
                contextMenu:     // define a context menu for each node
                $$("ContextMenu",  // that has one button
                        $$(go.TextBlock, "Change Color"),
                        { click: changeColor }) // more ContextMenuButtons would go here
                    )  // end Adornment
            new go.Binding("points").makeTwoWay(),              
            $$(go.Shape, { isPanelMain: true, stroke: "#e0e0e0", strokeWidth: 10 },
            new go.Binding("stroke", "color", function(c) { return colors[c]; })),
            $$(go.Shape, { isPanelMain: true, stroke: "white", strokeWidth: 3, name: "PIPE", strokeDashArray: [20, 40] })

Maybe your code should be looking at linkdata?