I just noticed today that local data declarations using constructor-style syntax also are showing up with light-blue highlighting. For example, using this code fragment:
ScriptHandle id(m_EntityId);
pScript->SetGlobalValue( ENTITY_ALIAS, id );
if I were to select id, both locations would show up with light-blue highlighting. In reality, of course, the first instance (where the data is defined and initialized) should use light-red highlighting.
Bottom line: be sure that constructor calls for local variables get light-red highlighting.