I write code, I am definitely not an artist, so having something like Asset Forge that allows me to cobble something half-way respectable together is a blessing. That said, I think I must be doing something incorrectly as when I export from Asset Forge (as OBJ) and import into Unity, while I get the model just fine, the materials are not just fine. I've exported as both merged and un-merged, and in both cases no textures or colors are associated with the materials that get imported. I can import a texture after the fact and apply it, but that's awfully painful.
I'm using Unity v5.6.2.