The wasn’t much of a process lol. I blocked out all the main colors with the airbrush and then used it to had two layers of highlights to the roof. Everything else was brush, dry brush and wash. I followed this guide: https://youtu.be/oSqbT0HO74U
I just matched the paint colors as best I could with cheap craft paints.
Side note: That video was how I found out about printable scenery and 3D printing. I was sold immediately lol