1. Open the Main product - Reviews section:
On the left sidebar of the Theme editor, click the Main product - Reviews section.
If this section does not exist on the available list, you can also add it by clicking the Add section button, then choose Main product - Reviews.
Click the section name from the available section list on the left sidebar to open the section settings.
Enable: turn on/off the background.
Pick a color: choose a color to set the background color. If the background is empty, the background color will be displayed.
Background image: pick or upload your image to display it as the background image.
Background size: set the size of the background image.
Background style: set the style of the background image.
Enable top gutter: turn on/off the space distance on the top of the section.
Enable bottom gutter: turn on/off the space distance on the bottom of the section.