Hey, sorry for the delayed response, just noticed the comment. For the FBX file you don't need a texture, it has terrain colors encoded into color attribute of meshes' vertexes. What you need is a material/shader that can use those vertex colors.
Thanks, glad to hear you like it! :) In that particular video with the air balloons the planet was randomly generated, but hand-made planets from Planet Painter could also be used.
