It's pretty easy to make your own skirt colors. Just duplicate and edit a .dds of the texture, put it into a .zip archive (you can look at one of the various other maps like the "textures.zip" in eppeldorf for how to structure the archive), and include a line in ClientArchives.con telling BF2 to open the archive.
For eppledorf that line is:
fileManager.mountArchive /Levels/eppeldorf/textures.zip Objects
Naming the .dds (and the exact structure of the .zip) will depend on which skirts you want to replace. You can find the current skirt textures in in the staticobjects folder, for instance for French-theatre trenches it would be under ...EA GAMES\Battlefield 2\mods\fh2\objects\StaticObjects\France\textures (named eu_trenches2_de_hurtgen.dds, eu_trenches2_de_PDH.dds, ect.).