Please help, FBX file keeps showing Solid Colors as Translucent

Hello, Could some please help me fix this problem I’m having with Translucency? I’m coloring an object black both on the outside and inside and for some reason when I save it as an FBX file and go to preview it I see right through the object. I’ve provided an image that explains my problem. If you have any questions please let me know so I can try to explain better if you don’t quite understand. Thanks.

Just a guess … View the SketchUp model in Monochrome.
Are all the faces oriented such that the front side (white) is facing outward?