Is your feature request related to a problem?

I have some issues with the export features, specially with large schemas.

• PDF will shrink the exported schema, zoom on text limited.
• PNG is ok, but the text quality is pretty bad when zooming (large schema again)
  So I use SVG.
  I am on Fedora latest, and default viewer shows the SVG (dark theme) with a dark background. Therefore, the text is not readable.

Conclusion, I have to export schemas as SVG. To be sure it is readable for all. I edit each of theme to add a white background.
I would like this operation to be automatic since SVG export it the only option that satisfies me (for the quality, I mean readability.)

Describe the solution you'd like

A simple option to add a white background on all SVG export.
As a modal, or as a configuration option on Gaphor.

Describe alternatives you've considered

As I said, I had no option but to edit all files generated by Export All diagrams as SVG.

Additional context

Under Preferences, I add an Export section with the folowing option :

• Add white background on SVG exports.

Why white ? Because text is black by default.