Transparent background handing

When you upload a .png file with a transparent background as a page background, the workspace takes one of its colours or some sort of a mix & fills transparent space with it. If you then change background colour, it changes the whole background to the colour it picked when the image was uploaded & the image isn't visible anymore.

Ideally, it would be possible to have a page background colour that could be changed and would fill in whatever transparent gap there is in the image.