I found these tools immensely useful during mCtrl development. Perhaps you will find them useful too.
That said, note they are not connected with mCtrl project, they are work of their respective authors and they are covered by their respective licenses.
This is a small tool to explore visual styles (aka themes) on Windows XP and later, as provided by UXTHEME.DLL.
It has been developed as an auxiliary tool to be used during the development of the mCtrl project but possibly other UI developers can find it useful too.
Great utility for tuning Win32API dialogs as well as for studying how various other Windows applications have designed their user interface.