I don't think Fill Graphic Overrides will make Zones transparent in Sections. I think you'll need to either fiddle with the Surface's Settings or just make the Layer the Zones are on wireframe or turned off. Display of Zones in Section
Brian Spears BIM Manager, Steele Group Architects Winston-Salem, NC AC26 USA on macOS
Brian thanks for your help. It turns to be more complicated than that, like you mentioned, Zones a are depended on surfaces, but also surfaces are depended on the section's own settings, like the uncut fills, fade distant element etc'- I have problems imagining/grasping such complex hierarchy. I don't exactly know which settings Archicad prefers over the other (I think its section settings > surfaces > overrides). I also think the program should not make things so complicated. I'm not sure yet it optimised with its interface in terms of being understandable. I turned off all the options I had for really nice graphics for the section, and now with a bit of cheating I can get the background of the zones to be transparent.