Add the following code to the `style.css' of your CHILDtheme:
background-color: rgb(2, 255, 255); /*change as required*/
Don't make any changes to a theme itself. Instead make the changes to a childtheme. Should the author of your original theme update the theme, your changes will not be overwritten. Your site with your adaptations will remain intact.
You don't have a childtheme yet?
1. Install and activate 'one click childtheme plugin
2. create the childtheme
3. activate the childtheme
4. Make the changes in the CHILDtheme!
- copy php files / css-file(s) of the original theme [as required] to the childtheme directory and edit them as required.