Found the theme color issue.
Server node color is customizable and new server nodes are created with background from window and saved in .pgadmin3.
I don't see the usefulness of this feature so I've attached patch that removes it.
I see there is alot of work to be done to modernize the usage of wxWidgets to take advantage of new widgets for trees, lists and toolbar and perhaps even the grid. Any interest in contributions towards this?
/Björn
PS. Dug alot into the code base to finally discover the above and noticed there is *alot* of work to do to properly go to wxWidgets 3.0+.