It can be done, but not all guns shipped that way...There are nickel guns with nickel sights, and others that shipped with blued sights...I suggest lettering any gun before altering it unless originality is not important to you... ...Ben
The Model 25-5 has the ramp base forged with the barrel. The red ramp is pinned to the base with a single pin. You may be able to locate a red ramp in nickel, but it would be a long search.