If you want to darken chrome trim, there are several ways you can do it. One of the easiest methods is using a special chrome-blackening solution, which can be found in many automotive stores or online. Before beginning, make sure to clean any dirt and debris from the trim with a mild soap and water mix. Once that's done, apply an even layer of the blackening solution onto the chrome with a paintbrush or lint-free cloth. After allowing it to sit for 10 minutes or so, rinse off thoroughly with cool water and let air dry completely before buffing lightly with a soft cloth. You can also use an oil-based black paint on your chrome trim if desired - just apply one thin coat over top of the existing finish; this will give it an extra level of protection while still giving you that darker look. Lastly, some people have had success by applying multiple coats of car wax on their chromed pieces as well – though this method may require more regular maintenance than other options!