One of my pages has a single image taking up some space on the page. The rest of the space (the space not occupied by the image), should be transparent: that is, whenever I send it to the printing service, the base color of the selected paper should be visible, without any ink being printed on it (not even white - the paper will have a base color/texture that I do not want to print over)

Currently exporting the page to a png file creates an image with my original image on a white background, since that is what the background in scribus is set to. I do not want this: I want the image to be on a transparent background.

I have taken a look in all possible menu options and I have been unable to find where can I set the background color, which currently seems to be white. I do not know if it is possible to set the background color of a page, and in case it is possible, if it is possible to set it to transparent.

How can I achieve this in scribus?