This is the vertex color painting material study that I worked for Unreal Engine 4 shader. For the floor tile material part, I used a "10 layer blend in" to have a procedural mask function. The tile design can be changed only with an RGBA mask image (It is explained well in https://www.artstation.com/sungho1114/blog). For the vertex color painting part, I used vertex node alpha channel to make it able to vertex paint because there are only two textures. I also added a power node after the vertex node to have a nice vertex paint pattern instead of having a blurry sphere brush. Sand and tile materials are made in Substance Designer and all the shaders on the screenshots are made and rendered in Unreal Engine 4.
Hires image - https://www.artstation.com/artwork/gJEkqm