put it on top of the green, save the .dds with a suffix (so blahblahblah_customname.dds , this is how _woodland textures are loaded too on a map by map basis)
then set the map to load a custom texture suffix in the init.con
Ye, Re-UVing the static to have it using a different part of the colour palette isn't really a very good idea unless you know exactly what your doing and its necessary.
As Rudd said, re-texturing the part of the palette you want the colour changed on is the simplest way of doing this. How ever this dose mean that you can't have multi-colours of the same object (if that's what your looking for) and also since these are texture palettes, many other statics also use these colours and as such, any change to one building will be a change to every single building that uses that colour as well which can have a negative impact on some statics that need to be green to look right or w/e so make sure after changing a texture, no other statics are affected negatively by the change on the map(s) you plan to use this new texture.