Either by the use of lacquers, wax polishing, or both.
Using chemical treatment, any desired colour can be obtained. Specialist companies should be consulted to identify the correct product for a particular project.
Bronze has been used for centuries to create statues, and is still the first choice for modern, striking works of art. The most widely-used alloys for such objects are leaded gunmetals, such as CC492K and CC491K.