Can you post a picture of the light?

We've been working on a large remodel project for a while now. There weren't many matte black fixtures available when we started, plus I could not find a full line of coordinated light fixtures to choose from.

I have found numerous vintage ones that I painted black. The finish gives them continuity, but there is enough difference to make them interesting.

I like both the Rustoleum 2X Ultra Cover Primer (in gray) and the same brand of Matte Black paint. As far as painting anything brass, it never seems to look "real", IMO.

Matte black works well, I’ve also used a ‘dark bronze’ hammered spray paint from the orange box that works well depending on what you are trying to achieve. The dark bronze looks almost black just slightly softer.

I find a dark metallic paint to give a better finish than matte black. Rust Oleum used to do a patina spray paint that was fantastic for light fixtures but it seems to have been discontinued. Light fixtures can be tricky to spray evenly and runs and sags may be less noticeable in a metallic.
When I spray fixtures, I prefer to remove all the screws for the globes and insert then into foam or cardboard so they can be sprayed easily.

I have never gone from silver to black but I have gone from silver to gold/bronze/brass. For metallic colors I prefer to use Rub and Buff because I think it looks more realistic and is easier to work with than paint. You simply rub it on and buff it off.

Here is a before and after using Rub and Buff. They have a few shades of gold/brass/bronze. I think I used three shades on this fixture.

Here is another example of RNB, this time in a different shade on a light fixture. It is covering white pvc that I cut because I wanted the stems to be longer then what were on the original fixture.

You can, but you need to sand down the polished metal to promote adhesion, otherwise the paint will come off with the slightest bump, try a 320 sandpaper or a soft scrubbing pad.