This is an update for this article.
I spent a few more hours trying to update the user interface and to make the tool a little easier to use.
Update 1: New options
The interface is more refined and has shortcuts to open the site directly from a context menu. New items in the "File" menu for easy access to SharePoint Theme files and folders.
Update 2: More Information at a glance
I've added an extra DataGrid View to show properties of the selected site or selected theme. This version also shows the theme preview.
Update 3: Easier to use interface
I've reduced the pop-ups and tried to bring is all together in the one window.
You can get the latest (v1.6.3) SharePoint Branding Tool here: