The ‘Command’ tab has some basic setup functions under it which are used to set up Status, Priority, and Tags entries.  (Task List Manager) comes with some default settings but they can be replaced or expanded as you desire:

The ‘Priority’ menu item launches the Priority entry screen where priority values can be entered or deleted and their sort sequence set or changed.

Use the plus and minus boxes to add and subtract items from the list.  The ‘color’ column for now is just there for future enhancements.  To change an item, delete it and then re-add it.  

The ‘Status’ and ‘Tag’ menu items will display those update screens.  They work the same as the ‘Priority’ screen.