Colours in ifc file

We are still having a couple of problems since Bentley changed the ifc exporter. On the plus side, the file sizes have gone down by about 50%.

The attached screenshot shows the same model, the left side exported by SS3, the right side by SS5. As you can see, both the file structure is different, bot also the colours of the objects.

Let's focus on the colour on this thread. The one green wall on the top of the building is selected, that explains the green colour in both models. But if you have a look at the other objects, almost everything is white in SS5, regardless of if it is a wall or a slab.

Why that - and how can I change that?

Other questions: Why does it show different disciplines - SS3 shows Structural (correct), SS5 shows Architectural (wrong)?