The theme allows changing the background image and background color using the below options. Before displaying the background image and color you need to enable the boxed layout option.
1. Background Image
In this option, you can add the background image with image position and image size options.
Appearance >> Customize >> Colors & Background >> Background Image
2. Background Color
In this option, you can add the background color.
Appearance >> Customize >> Colors & Background >> Background Color