Changing background colour and border style and colour of math result box

[Emiral46]

I cannot change the appearence of the math result panel to the colours I want which really annoys me. When I try to set background colour and border to math-label in css configuration, it ends up with something like this:

I want to modify the look the old black box with white border for math operations and cannot find any proper way to do this? Is it possible to add support for modifying the math result box so I can modify it?

[nwg-piotr]

Yes, I only added a CSS ID for the Gtk.Label. The window is defined internally.