Changing ground textures?

[Stoferr]

Yeah, i need a but weird mod. I would like to do some greenscreen video editing with Empire, and for that, I need all ground textures turned into a green solid color.

I don't ask anyone to that, as it is most likely a lot of textures to change, but how do i do it? In which can i change the groundcover textures? Like grass, sand, dirt etc.

[Stoferr]

Please someone help! No one knows in which .pack file the ground textures are stored?