In 3D, you should check Cut Surface Display settings. Go to: View > Elements in 3D View > Filter and Cut Elements in 3D.
You'll see Cut Surface Display, and make sure "Use Element Attributes" is used - this will display the Building Material's Surfaces instead of a unified Surface.
For Sections/Elevations, check their Settings under "Model Display" and see what setting you have for "Cut Display" > Fill Cut Surface with:
To change the appearance of any Cut Surface (fill/pens/surface) then you can select an element and open the Building Materials settings to review their appearances (because of the selection they will be highlighted in the list).
Hope that helps.
James Badcock
Graphisoft Senior Product Manager