Adding places from KML [Keyhole Markup Language] files

I would like to learn how to create KML files that are acceptable to Gramps on the Geography view, when I right-click on the map and select “Add place from KML”. I have tried creating polygons in Google Maps and Google Earth, and saving them as KML files, but nothing happens when I add them. The example in the wiki looks like it has a shaded polygon. Does anyone have any samples that work? Thanks.