I’m not sure if this has been mentioned already, but I couldn’t find it.
Many times when I export an image from the viewport (or use GH animate slider) with a higher resolution than my viewport is currently showing, seemingly random objects will have white edges instead of black or their respective colour. So far no settings would change this.
It happened with both .png and .bmp export. When animating in GH I usually export as .bmp to not loose information when making video clips.
I’ll try changing file formats next time I have a chance. In my experience this also only happened when the export resolution was significantly higher (for example, 4K export on a normal HD screen). It seems to be working on another computer with a high-res display for now.