I am creating a chainlink fence macro for a specific project. (Can't find a suitable one out there)

I have created the texture to apply to an object in FSDSv2 and used FSDS to 'make the texture tranparent'.  However when viewed in FS2002 you can see through the fence okay but all the chain, posts and signs have turned a uniform grey colour.  Any ideas why this has happened.

Tried playing with the Opacity and Levels but to no avail and also found this happens with other textures I had found.  Any help appreciated. Thanks ???