I recently completed another board for Didcot Wargames Club. This board was themed to fit in with the corrupted land gaming mat from pwork wargames. The terrain was a set of 3D-printed ruins, with some tentacles and corruption oozing out of the walls.
I undercoated the walls brown, followed by painting some burnt sienna on the brickwork. The walls were then given a highlight of a lighter tan colour. The corruption was basecoated with sap green, then given a highlight drybrush of a mix of sap green and white.
I then added some fluorescent green paint, followed by a mix of the fluorescent green and yellow.
The ruins work well in the GW tournament format, with acrylic bases to simulate the area of the ruins.