thunar archive dialogue box new look

[Piscium]

Hi all,

If I  right click on a file or folder I can select the "Create
Archive" option. This brings a dialogue box to set file name, etc.
There was a recent design change in this box, and the colour now is
light whereas I have Xfce set with a dark theme.

The last change to Thunar was last year, likewise to its archive
plugin, so where does this recently-changed dialogue box come from? Is
there a way to set it with a dark theme?