Your addons are white because:
1. You didn't pack your textures into the .pbo, or...
2. They are the wrong format. or...
3. The texture paths in your .p3d don't point to your textures.
Most of the time it's #3. Maybe you know: each polygonal face in your .p3d has a texture path associated with it.
And these paths look something like this:
name of the pbo without extension\[name of additional folders in your pbo (if any)]\name of your texture file with extension
To set the texture directory, go to File-> Options in Oxygen.
To view the texture paths in a .p3d (and maybe edit them, but beware, you cannot modify their length), i suggest you use a hex editor.
Good luck with that retuxering