The background image is implemented in the styling of the template. There is a class, page-background, that sets the background. If you want to remove the styling for the background, you can simply remove the class from the container on the Home page in the Studio Pro, or you can edit the .scss file that contains the class, found at <branch>/theme/styles/web/sass/app/_card.scss; just update the styling of the .page-background definition to suit your needs. You can also specify a different image by changing the value of the path for $bg-image variable in the _custom-variables.scss file (same folder as _card.scss)
Hope this helps.
So I’ve taken a look at the scss files. The particular classes that the Home page has are page-dashboard and page-dashboard-actions, neither of which I can find in any of the .scss files. I’ve tried removing them, manually entering a background-image input in the “Style” box in Properties for that page (also testing with other background css options like gradients or single colors), and tried changing the $bg-image filepath. None of which change the background image. Is there something else I’m missing?