@sargentcrunch- man I done in in 1 min. just to show him how to tile this elements. He can map 2 models or 2 color variations on this texture, or just make 512_512, come one. IMO vertex paint isn't necessary and require quite complicated shader. Not worth.
I quickly made this as a test: I've cut up the mesh at the parts that needed a different color. Then detached that part, so you get a really sharp blend. Then after I've assigned the colors I painted in a few spots of AO and shadows. In Unity I made special shader that multiplies a diffuse texture with the vertex colors.