So, I can't really edit when the square is gray, But I can edit the square is blue or yellow. The question is how can I make the square gray to blue or yellow Sorry but English is not my first language. You can see the screenshot. ASAP please
Use Ctrl + Shift + F11 to switch the Document Toolbar from Live to Design view (see screenshot). It may not look pretty but it should be editable. If not, chances are you're working with a Template driven child page in which case you must open the Template.dwt file to edit the menu.