diff -r e0f6f3c31150 -r bb63da144239 client/js/paper-renderer.js
--- a/client/js/paper-renderer.js	Thu Jan 31 18:53:08 2013 +0100
+++ b/client/js/paper-renderer.js	Fri Feb 01 12:48:40 2013 +0100
@@ -20,7 +20,14 @@
     _EDITOR_GRADIENT : new paper.Gradient(['#f0f0f0', '#d0d0d0']),
     _CLICKMODE_ADDNODE : 1,
     _CLICKMODE_STARTEDGE : 2,
-    _CLICKMODE_ENDEDGE : 3
+    _CLICKMODE_ENDEDGE : 3,
+    _USER_PLACEHOLDER : {
+        color: "#000000",
+        title: "(unknown user)",
+        get: function(attr) {
+            return this[attr] || false;
+        }
+    }
 }
 
 Rkns.Renderer.Utils = {
@@ -257,7 +264,7 @@
     this.circle.position = this.paper_coords;
     this.title.content = this.model.get("title");
     this.title.position = this.paper_coords.add([0, Rkns.Renderer._NODE_RADIUS + 1.5 *Rkns.Renderer._NODE_FONT_SIZE]);
-    this.circle.strokeColor = this.model.get("color") || this.model.get("created_by").get("color") || "#000000";
+    this.circle.strokeColor = this.model.get("color") || (this.model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color");
     this.edit_button.moveTo(this.paper_coords);
     this.remove_button.moveTo(this.paper_coords);
     this.link_button.moveTo(this.paper_coords);
@@ -418,7 +425,7 @@
         _p1b = _p1a.add(_delta), /* to differentiate inbound and outbound links */
         _a = _v.angle,
         _handle = _v.divide(3),
-        _color = this.model.get("color") || this.model.get("created_by").get("color") || "#000000";
+        _color = this.model.get("color") || this.model.get("color") || (this.model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color");;
     this.paper_coords = _p0b.add(_p1b).divide(2);
     this.line.strokeColor = _color;
     this.line.segments[0].point = _p0a;
@@ -592,14 +599,15 @@
     + '<p><label><%=l10n.edit_title%></label><input class="Rk-Edit-Title" type="text" value="<%=node.title%>"/></p>'
     + '<p><label><%=l10n.edit_uri%></label><input class="Rk-Edit-URI" type="text" value="<%=node.uri%>"/><a class="Rk-Edit-Goto" href="<%=node.uri%>" target="_blank"></a></p>'
     + '<p><label><%=l10n.edit_description%></label><textarea class="Rk-Edit-Description"><%=node.description%></textarea></p>'
-    + '<div class="Rk-Editor-p"><label>Node color</label><div class="Rk-Edit-ColorPicker-Wrapper"><span class="Rk-Edit-Color" style="background:<%=node.color%>;"></span><ul class="Rk-Edit-ColorPicker">'
-    + '<% print(Rkns.pickerColors.reduce(function(m,c) { return m + "<li data-color=\'" + c + "\' style=\'background: " + c + "\'></li>"},"")); %></ul></div></div>'
+    + '<div class="Rk-Editor-p"><label>Node color</label><div class="Rk-Edit-ColorPicker-Wrapper"><span class="Rk-Edit-Color" style="background:<%=node.color%>;"><span class="Rk-Edit-ColorTip"></span></span><ul class="Rk-Edit-ColorPicker">'
+    + '<% print(Rkns.pickerColors.reduce(function(m,c) { return m + "<li data-color=\'" + c + "\' style=\'background: " + c + "\'></li>"},"")); %></ul><span class="Rk-Edit-ColorPicker-Text">Choose color</span></div></div>'
     + '<p><label><%=l10n.edit_image%></label><input class="Rk-Edit-Image" type="text" value="<%=node.image%>"/><img class="Rk-Edit-ImgPreview" src="<%=node.image%>" /></p>'
     + '<p><label><%=l10n.created_by%></label> <span class="Rk-UserColor" style="background:<%=node.created_by_color%>;"></span><%=node.created_by_title%></p>'
 );
 
 Rkns.Renderer.NodeEditor.prototype.draw = function() {
-    var _model = this.node_representation.model;
+    var _model = this.node_representation.model,
+        _created_by = _model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER;
     this.editor_$
         .html(this.template({
             node: {
@@ -607,9 +615,9 @@
                 uri: _model.get("uri"),
                 description: _model.get("description"),
                 image: _model.get("image") || "",
-                color: _model.get("color") || _model.get("created_by").get("color") || "#000000",
-                created_by_color: _model.get("created_by").get("color"),
-                created_by_title: _model.get("created_by").get("title")
+                color: _model.get("color") || _created_by.get("color"),
+                created_by_color: _created_by.get("color"),
+                created_by_title: _created_by.get("title")
             },
             l10n: this.renderer.renkan.l10n
         }));
@@ -643,7 +651,7 @@
     );
     this.editor_$.find(".Rk-Edit-ColorPicker li").hover(
         function() { _this.editor_$.find(".Rk-Edit-Color").css("background", $(this).attr("data-color")); },
-        function() { _this.editor_$.find(".Rk-Edit-Color").css("background", _model.get("color") || _model.get("created_by").get("color") || "#000000") }
+        function() { _this.editor_$.find(".Rk-Edit-Color").css("background", _model.get("color") || (_model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color")) }
     ).click(function() {
         _model.set("color", $(this).attr("data-color"));
         _this.redraw();
@@ -689,28 +697,31 @@
     '<h2><span class="Rk-CloseX">&times;</span><%=l10n.edit_edge%></span></h2>'
     + '<p><label><%=l10n.edit_title%></label><input class="Rk-Edit-Title" type="text" value="<%=edge.title%>"/></p>'
     + '<p><label><%=l10n.edit_uri%></label><input class="Rk-Edit-URI" type="text" value="<%=edge.uri%>"/><a class="Rk-Edit-Goto" href="<%=edge.uri%>" target="_blank"></a></p>'
-    + '<div class="Rk-Editor-p"><label>Edge color:</label><div class="Rk-Edit-ColorPicker-Wrapper"><span class="Rk-Edit-Color" style="background:<%=edge.color%>;"></span><ul class="Rk-Edit-ColorPicker">'
-    + '<% print(Rkns.pickerColors.reduce(function(m,c) { return m + "<li data-color=\'" + c + "\' style=\'background: " + c + "\'></li>"},"")); %></ul></div></div>'
-    + '<p><label><%=l10n.edit_from%></label><span class="Rk-UserColor" style="background:<%=edge.from_created_by_color%>;"></span><%=edge.from_title%></p>'
-    + '<p><label><%=l10n.edit_to%></label><span class="Rk-UserColor" style="background:<%=edge.to_created_by_color%>;"></span><%=edge.to_title%></p>'
+    + '<div class="Rk-Editor-p"><label>Edge color:</label><div class="Rk-Edit-ColorPicker-Wrapper"><span class="Rk-Edit-Color" style="background:<%=edge.color%>;"><span class="Rk-Edit-ColorTip"></span></span><ul class="Rk-Edit-ColorPicker">'
+    + '<% print(Rkns.pickerColors.reduce(function(m,c) { return m + "<li data-color=\'" + c + "\' style=\'background: " + c + "\'></li>"},"")); %></ul><span class="Rk-Edit-ColorPicker-Text">Choose color</span></div></div>'
+    + '<p><label><%=l10n.edit_from%></label><span class="Rk-UserColor" style="background:<%=edge.from_color%>;"></span><%=edge.from_title%></p>'
+    + '<p><label><%=l10n.edit_to%></label><span class="Rk-UserColor" style="background:<%=edge.to_color%>;"></span><%=edge.to_title%></p>'
     + '<p><label><%=l10n.created_by%> </label><span class="Rk-UserColor" style="background:<%=edge.created_by_color%>;"></span><%=edge.created_by_title%></p>'
 );
 
 Rkns.Renderer.EdgeEditor.prototype.draw = function() {
-    var _model = this.edge_representation.model;
+    var _model = this.edge_representation.model,
+        _from_model = _model.get("from"),
+        _to_model = _model.get("to"),
+        _created_by = _model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER;
     this.editor_$
         .html(this.template({
             edge: {
                 title: _model.get("title"),
                 uri: _model.get("uri"),
                 description: _model.get("description"),
-                color: _model.get("color") || _model.get("created_by").get("color") || "#000000",
-                from_title: _model.get("from").get("title"),
-                to_title: _model.get("to").get("title"),
-                from_created_by_color: _model.get("from").get("created_by").get("color"),
-                to_created_by_color: _model.get("to").get("created_by").get("color"),
-                created_by_color: _model.get("created_by").get("color"),
-                created_by_title: _model.get("created_by").get("title")
+                color: _model.get("color") || _created_by.get("color"),
+                from_title: _from_model.get("title"),
+                to_title: _to_model.get("title"),
+                from_color: _from_model.get("color") || (_from_model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color"),
+                to_color: _to_model.get("color") || (_to_model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color"),
+                created_by_color: _created_by.get("color"),
+                created_by_title: _created_by.get("title")
             },
             l10n: this.renderer.renkan.l10n
         }));
@@ -735,7 +746,7 @@
     );
     this.editor_$.find(".Rk-Edit-ColorPicker li").hover(
         function() { _this.editor_$.find(".Rk-Edit-Color").css("background", $(this).attr("data-color")); },
-        function() { _this.editor_$.find(".Rk-Edit-Color").css("background", _model.get("color") || _model.get("created_by").get("color") || "#000000") }
+        function() { _this.editor_$.find(".Rk-Edit-Color").css("background", _model.get("color") || (_model.get("created_by") || Rkns.Renderer._USER_PLACEHOLDER).get("color")); }
     ).click(function() {
         _model.set("color", $(this).attr("data-color"));
         _this.redraw();