The General tab allows you to set the type of site width displayed and apply a background color. You can also change the body background color of the website.
1. Log into your Blogger dashboard.
2. Go to Theme > Customize > Advanced > General.
3. Make necessary changes > Save.
Changes the value to apply to the wide container of the entire site. A wide container or full wigth:
Full width: Value 0px to enable.
Contained: Value 1px to enable.
Choose the body background color and the contained background color.
Body background: Change the body background color.
Contained background: Change the contained background color.