Hi,
The issue was originally described here: https://bugs.winehq.org/show_bug.cgi?id=34825
I bisected both issues, but I'll create separate thread to the issue with file dialog.
First bad commit that causes black background on icons is: [ b81a7d976e3c3de36a01401d125871d3014e6c67 ] gdi32: Always use the DIB engine for monochrome bitmap rendering.
To see how the issue looks like, I attached small screenshots.