Do you have the rifle prop that I linked to quite a while back? That's got a big scope & a brassy / steampunk look iirc.
Dang sometimes civ colour is difficult to place without ruining the overall look of the unit. How about civ-coloured goggle lenses?
Here's some red ones for example
http://got-steam.com/Scripts/prodView.asp?idproduct=18
And some green & blue ones
http://walyou.com/steampunk-solid-brass-goggles/
If you could make the goggles a more brassy colour then all the better.
Well, you should post at least one version with no civ color, IMHO. That would be my choice. As for Civ-coloring, I like the 'goggle lenses' idea - it's unobtrusive and would be spotted immediately by a player. Making the whole shirt civ color would be the traditional solution, I think, so your options are open. Very glad to hear of your progress.