Added a menu item to reset the pen color (to use again the plotColorPalette based color). Moved the saving/loading code to the SensorNode class (as with the other properties).

GUI/SensorNode.cs

@@ -4,7 +4,7 @@
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/.
  
-  Copyright (C) 2009-2012 Michael Möller <mmoeller@openhardwaremonitor.org>
+  Copyright (C) 2009-2016 Michael Möller <mmoeller@openhardwaremonitor.org>
 	
 */
 
@@ -22,7 +22,7 @@ namespace OpenHardwareMonitor.GUI {
     private UnitManager unitManager;
     private string format;
     private bool plot = false;
-    public Color? penColor = null;
+    private Color? penColor = null;
 
     public string ValueToString(float? value) {
       if (value.HasValue) {
@@ -61,6 +61,10 @@ namespace OpenHardwareMonitor.GUI {
 
       this.Plot = settings.GetValue(new Identifier(sensor.Identifier, 
         "plot").ToString(), false);
+
+      string id = new Identifier(sensor.Identifier, "penColor").ToString();
+      if (settings.Contains(id))
+        this.PenColor = settings.GetValue(id, Color.Black);
     }
 
     public override string Text {
@@ -77,6 +81,22 @@ namespace OpenHardwareMonitor.GUI {
       }
     }
 
+    public Color? PenColor {
+      get { return penColor; }
+      set {
+        penColor = value;
+
+        string id = new Identifier(sensor.Identifier, "penColor").ToString();
+        if (value.HasValue)
+          settings.SetValue(id, value.Value);
+        else
+          settings.Remove(id);
+
+        if (PlotSelectionChanged != null)
+          PlotSelectionChanged(this, null);
+      }
+    }
+
     public bool Plot {
       get { return plot; }
       set {