The Glossary Viewer Options Colors... menu item opens the Glossary Viewer Colors dialog:
There you can define background colors for specific glossary entries displayed in the Glossary Viewer Entry Table. Coloring can help you easily identify where glossary entries stem from.
The Shell Color is the background color that is used to display shell entries.
The Include Color is the default color assigned to an include at the time it is added.
The #Shields Color is the background color that is used to display all entries which stem from the Shield Glossary Shell.
The #Prime Color is the background color that is used to display all entries which stem from the Prime Glossary Shell.