Steps to Reproduce

1. Open the new file dialog
2. icons on buttons are missing on right of the filename, the buttons are present but invisible, when passing over with the mouse the buttons are shown (like a ghost) but the icons are missing

Current Behavior

Icons in open file dialog are broken.

Some suspect are on libgdiplus, some folks have obtained a working icons downgrading to 6.0.2 (Using ubuntu 18 repositories for ubuntu 18 distribution)

Line 175 in
https://github.com/mono/mono/blob/master/mcs/class/System.Windows.Forms/System.Windows.Forms/FileDialog.cs

imageListTopToolbar.ColorDepth = ColorDepth.Depth32Bit;

Seem to be the culprit

Expected Behavior

Icons are to be on the bar.

On which platforms did you notice this

[ ] macOS
[X ] Linux
[ ] Windows

Version Used:
Devuan 9.0 Ascii - (Debian Stretch)

Latest repo for Debian Stretch used

Mono JIT compiler version 6.4.0.198 (tarball Tue Sep 24 01:20:06 UTC 2019)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
Interpreter: yes
LLVM: yes(610)
Suspend: hybrid
GC: sgen (concurrent by default)