How about as 2 light-weight and mutually exclusive modules for fighters, you allow for a ‘Stealth applique’ and a ‘Mirrored applique’. The mirrored applique would simply be a reflective surface painted onto the fighter that would reflect energy fire, but do nothing for missiles (except give them better guidance locks). The stealth applique would be a matte surface designed on making the little ship harder to spot, making it almost impossible to hit the fighter with a missile (unless a guidance beam is involved) and possibly having a side effect of less accurate fire of all types. As these are only ‘paint thin’ applications and not actual armor, they would not significantly weigh down the fighter, but they would also be especially non-durable, only able to survive zero or one successful hits from any source.
These would be options only for fighters (or as specially designed hulls for same), as while you might be able to clean & polish a fighter with relative ease, doing the same for a generations-old dreadnaught poses an entirely different magnitude of problem.