GoogleFrog, they are hand painted. Some of the closeup shots at https://tabletopannihilation.imgur.com/
show some of the detail that would not be printable. Painting was time consuming. I would really like to get a color 3D printer as my next step in this project.
I just started playing ZK so I haven't tried any ZK models yet, but I'll print some of my favorites soon. I think they will be easier to print because they appear to be complete 3D models. The TA models are not solid objects, they are hollow, made of 2D faces with open undersides; takes some work to make them solid/printable.