Change page setup of a Google Doc

On your computer, open a document in  Google Docs . 
 In the toolbar, click  File     Page setup . 
 Go to the setting you want to change:
 
 Orientation 
 Paper size 
 Page color 
 Margins 
 
 
 Make your changes. 
 Click  OK . 
 Optional: To make new documents open with the settings you chose, click  Set as default.