From Paul Martz and David Glenn,

"From David Glenn and Paul Martz. This change adds support for the NO_COLOR bit in the Vertex records' flags field. If NO_COLOR is set, and PACKED_COLOR is not set, the code will now properly default to using the face color at those vertices. See the osg-users thread "Open Flight characteristic not reflected in the current OSG" for more info."

and

"In consultation with David Glenn, it appears we needed to change a second file to correct how OpenFlight handles transparency when vertices have NO_COLOR. "

src/osgPlugins/OpenFlight/GeometryRecords.cpp

@@ -254,7 +254,10 @@ public:
             {
                 // Use face color if vertex color is -1 in a gouraud polygon.
                 // http://www.multigen-paradigm.com/ubb/Forum1/HTML/000967.html
-                colors->push_back(_primaryColor);
+                // Incorporate Face transparency per osg-users thread "Open Flight
+                // characteristic not reflected in the current OSG" (Sept/Oct 2011)
+                colors->push_back(osg::Vec4(_primaryColor.r(), _primaryColor.g(), 
+                    _primaryColor.b(), ( 1.0 - getTransparency() ) ));
             }
         }