I am pretty equal opportunity when it comes to wearing different metals together. Not only do I style pieces made with different metals together I also combine different metals in a single design in my Raven and Stone jewelry pieces. Oxidized silver and gold go really well together, as do antiqued brass and gold. Start mixing in stones, pearls, textures and leather and you get an even more interesting look. The contrast creates a fresh look
The trick with mixing metals (and other materials) together in jewelry is to choose pieces that work well together and not to mix just for the sake of mixing. A big gold cuff and a thin silver chain bracelet will not do much for each other. But that same cuff with a thicker multi chain (and mixed metal perhaps) bracelet will get you the desired look. Add some pearls in as well for more contrast and voila!
Raven & Stone