Hi,
Alot will depend on what look you are going for. A brand new propeller can be quite shiny with extensive polishing marks, but once a vessels been in service for a while a bronzish color can be very suitable (for many propellers).
Here is a picture of a Flower Class Corvette's (HMCS Sackville's) propeller that has been sitting outside for quite some time.
Meanwhile here is a modern destroyer, with highly polished props (prior to launching - I believe).
Pat