In this new track, with GP4 Builder, as the minutes pass, the grandstands begin to paint green ... Finally, all the stands are green. In the game the stands are green. Wad contains the corresponding tex files for each object.
There's a fix green object feature in GP4B in Action menu but it's supposed to fix meshes imported from Z-modeler and I never saw GP4B creating green objects by itself so far. weird...
The last remaining green screens in the 2017b capture are most probably due to a green illumemissive material tint for these objects. Or a green tint for vertices themselves (if so, using the global lighting/shadowing feature could override them with white color)