I tied all the buildings in with the same colours and used the same blend as on my war board (dark brown, light brown, mustard, cream).
Here's the Firestorm Redoubt and a Vengeance Weapons Battery.
And the other one.
The Aquilla Strongpoint with Macro-Cannon... and a Wall of Martyrs Defence Line
And pretty soon I'll be posting the battle report of the Ork attack on this set-up...