There are a number of clever ways to ensure your wedding band complements your beloved engagement ring. Wedding ring shapes play a role in the way neighbouring bands sit alongside one another; have you considered a contour that hugs your engagement ring tightly? Complementery engravings are also a beautiful means of tying two rings together.
There are no rules when it comes to combining metal colours. In fact, a fusion of hues is a fun approach to making your ring stack all yours; also enabling you to wear a variety of metals elsewhere on your body. If you plan on stacking both rings together, it's just important that your wedding band's metal matches that of your engagement ring on the Mohs Scale of Hardness.
Though it's traditional in many Western cultures to wear your wedding band beneath your engagement ring on the fourth finger of your left hand, in the contemporary context there's really no such thing as the 'correct way' to wear your bridal rings. You could stack your engagement ring and wedding band, wear the rings on separate hands or squirrel your engagement ring away altogether.