For me it is a matter of the color of the truck and what trim the truck has. I like black grills on a solid color truck (no two tones) and no side trim. Even single color trucks should be a lighter color light white or ochre or light olive for a black grill to look good in my opinion.
Dark color trucks with two tone (white) and trim packages should have the factory silver colored grill insert.
Of course the golden rule of owning the truck is you can do what ever you like no matter what
