BUG: SpatialObject writes object color

The MetaSceneConverter code did not copy the SpatialObject's color
to the metaObject being written.

Color wasn't being copied from the SpatialObject to its Meta
representation for writing.

Modules/Core/SpatialObjects/include/itkMetaSceneConverter.hxx

@@ -355,6 +355,11 @@ MetaSceneConverter<NDimensions, PixelType, TMeshTraits>::CreateMetaScene(Spatial
       currentMeta->ParentID((*it)->GetParent()->GetId());
     }
     currentMeta->Name((*it)->GetProperty().GetName().c_str());
+    currentMeta->Color((*it)->GetProperty().GetRed(),
+                       (*it)->GetProperty().GetGreen(),
+                       (*it)->GetProperty().GetBlue(),
+                       (*it)->GetProperty().GetAlpha());
+
     this->SetTransform(currentMeta, (*it)->GetObjectToParentTransform());
     metaScene->AddObject(currentMeta);
     it++;