Once upon a time I experimented with using bluing chemicals to 'blue' or darken brass. Tried using cold blue on clean, cold degreased brass, preheating the blueing solution on cold and preheated brass, and just room temp solution on preheated brass. The brass was some scraps that seemed/looked to be of the same metal softness/hardness of the brass grip frame of my then Euroarms 51 Navy. Used a propane torch to gently heat the brass and solutions. Used a variety of bluing solutions. Some Caseys brass blacking, Brownell's Oxpho-Blue, Birchwood Casey's cold blue, and some old Herter's stuff that had been sitting on the shelf for a few years, can't remember the name, but it was a good product. In using the different methods, I ended up with a variety of end results. All the way from a dull black matt to semi-shiney black finish and a molted sort of finish that resembled case hardening. I never did do a complete grip frame, although I tried one of the procedures on the bottom of the grip frame on the '51 Navy (think it was the one of pre-heating the brass (just sort of warm) and applying the blueing. Never did achieve the same bluing color of the barrel/cylinder. I was able to sand and polish the color off. Put doing the whole grip frame on the back burner, maybe sometime may try again. Can't say how it would wear, but it's easy to apply and change results.