They dont leave even their metal armors so...but more different armors would be fun.
Back to subject, they have green outlines so...whats the problem ?
They could wear NCR armor for guards moving through NCR except Gun Runners caravan (they need to use normal CA like their brothers from fortress). All caravans moving to north,san Francisco etc could use desert one. Still its just a skin, more work and problems. I think green outlines should be enough guys.