If restoration of the trim is needed, I’d recommend Solution Finish, which comes in Gray or Black.
For protection after restoring, you could use Pinnacle Ceramic Trim Restorer, Solution Finish Over the Top, or the Cerakote/Griots Ceramic Trim Wipes. All should darken nicely.
I just bought and tried Meguiars new Ceramic Trim Restorer and Protectant. On trim that was greyish it brought it back nicely after a coat. I put a second coat on and it got 'black'. A 3rd and it was jet jet black. I can't speak on how long it lasts as it hasn't even been a week, but the darkening aspect of it seems to be a win.
If it needs restoration then stick with Solution Finish and a trim sealant. SF offers Over the Top to compliment Solution Finish. Do not put a coating on it if it needs restoration.
If the trim is still fairly new then a trim coating would be a good option. I have used CarPro DLUX for a long time. Lately I have been enjoying Poorboys Ceramic Trim Coating.
I love Solution finish. It did not win in the test Scott HD did, you might want to look at his videos when it comes to choosing products. He is really great at submiting a lot of products in comparative tests, and you can see the evolution of each products over time. I still use Solution finish and do recommend it, but if memory serves there were 2 better products on the market.