The default blue folder icon changes to white when “Use Label Colour in / Icons” is selected, even when the folder in question has no label. Is this intentional?
You upgraded the project from 1.x; in 1.x “No Label” was white. Delete the white “No Label” from Project > Meta-Data Settings…
I did that already, as mentioned in my other post about labels. The only “No label” is the uncoloured one (with an “x” when editing labels). There are no white labels.
Oh, wait, sorry, I’ve been staring at the screen coding so long that I missed the completely bleedin’ obvious. 
When you turn on labels for icons, folders are supposed to turn white. Otherwise the tinting wouldn’t work properly and they’d all end up shades of brown or something, or you’d if you had a blue label it could be hard to tell it from the actual blue folders.
All the best,
Keith