Adding an antique finish (black) to the ring will bring out the details in the pattern. The black color will go into the grooves of the detail and make them more noticeable. I think that will look nice.
I apologize for not responding to you sooner. For gold jewelry, the process that I''m most familiar with (there may be more) is where a black paint is applied. This paint is specifically made for jewelry. I do want to mention that it can be removed with acetone, so you need to be careful around nail polish remover, etc. For sterling silver it is an oxidation process.