How to change that pink color when drag link?
reference example Draggable Link
If you are talking about customizing appearances when the user is drawing a new link, you want to customize the LinkingTool. Please read GoJS Tools -- Northwoods Software
i have found thins one when drag node to node
diagram.toolManager.linkingTool.temporaryFromNode = tempfromnode;
but i need to change the custom appearance when drag link from palette to canvas upon node Draggable Link
Customize the temporary Nodes of the destination Diagram’s LinkingTool: