Linux GTK issue - Button icons are not visible in open/save file dialog boxes

[bitrot-alpha]

On GNOME desktop, the button icons are invisible in these dialog boxes.

I'm not actually sure if this is a problem with this project or upstream, as there is a lot of jank going on in GTK and GNOME..
I tested with both OpenSUSE Tumbleweed and Fedora 36.

I'll attach a .txt file of when I ran MemcardRex with MONO_LOG_LEVEL=debug.
debug_log.txt

[ShendoXT]

Hmmm, that's on mono... Dialogs are provided by the system:

    OpenFileDialog openFileDlg = new OpenFileDialog
    openFileDlg.ShowDialog()

The proper way for GTK would be to use FileChooserDialog provided by the GTK# but then
the whole app might as well be ported to GTK# to avoid interface glitches because WinForms are simulated on Linux.

If anyone is willing to do so I'll be happy to help as much as I can. Cocoa for macOS would be nice too 😜