How to create my own theme?

 
A themes consists of at least one file, located in "%gadgetDir%\Themes\XXX.xaml".
It's a xaml file and can be edited with any test editior of your choice, e.g. Notepad. Do NOT remove any Style-, Template- or Color-block, otherwise the gadget won't load or will throw errors when your theme is selected. You can add, change and remove Setters.
Optionally you can define an "ImageFile" attribute. This image is shown in settings dialog. If there's no ImageFile defined for a theme, a "no preview available" message will be displayed in settings dialog.
The name displayed in settings dialog is defined in "Description" attribute, this attribute is obligatory!
XXX.xaml also needs to have an "Edition" attribute, make sure you've defined the right Edition(s). Multiple editions are separated by semicolon.
Possible editions: "SM3RTM" = System Monitor 3.0 RTM, "SM3SDCRTM" = System Monitor 3 ShutDownControl-Edition 3.0 RTM

Example:

<SystemMonitor3 Description="your theme name" ImageFile="optionale_image_file.png" Edition="SM3RTM"/>