Open your Google Docs document
Click File
Click Page setup
Click the Page color box
Choose a color
Click OK
To change the background of only part of the document, select the text
Click the Highlight color icon
Choose a highlight color
Open your Google Docs document
Click File
Click Page setup
Click the Page color box
Choose a color
Click OK
To change the background of only part of the document, select the text
Click the Highlight color icon
Choose a highlight color