Importing 3d models

Heya, I’ve been have really big issues when trying to import 3d models into Toon boom, Can someone please explain why is every model I import grey, with no textures colours or details! I’ve tried

Importing every supported file type, no luck.
Letting Toonboom convert every supported file type to FBX as I import, no luck.
Converting different 3d model files with Autodesk FBX converter first (previous forum post mentioned as a possible solution), no luck.
Converting textures to mtl files and importing with the 3d model (another possible solution i read about), no luck.
Downloaded trial of maya and rendered them, no luck.

They are all grey! (although one model was dark green I was over joyed…)

It’s very frustrating how Toonboom says it does all this stuff yet from what I can tell it does not… or I’m a clueless noob missing something? Either way I’d appreciate any help as it’s very frustrating!