Icon of MFWorkplaceTreeNodeFolder and MFWorkplaceTreeNodeCIS

Is that possible to change icon of MFWorkplaceTreeNodeFolder or MFWorkplaceTreeNodeCIS classes ?

Yes, MFWorkplaceTreeNodeCISPage etc. offer a second constructor in which the image can be passed (“imageURL”).
Please pay attention: the icon need to be defined relative to the HTMLBasedGUI directory (in which the workpalce is running). I.e. you have to name it: "…//images/xyz.gif.