As a contractor I've never encountered such a request. You could never really "match" the ceiling paint anyway because your painter is in all likelihood using a flat white latex paint for the ceiling, which you could not spray onto plastic or metal and expect it to adhere - and any glossier alkyd or lacquer paint that could adhere to a light trim would never look the same as the ceiling paint anyway. That's because different sheens change the perception of color, even with a 'perfect' color match.

Finally, in my experience all light trims tend to yellow a bit over time (especially with hotter bulbs, e.g. halogen) so it's a bit of a waste of time to paint something that won't stay the same color for very long anyway.

Leave the light trim as is.

Xim primer then paint with the flat latex paint we used to do it all the time but it has fallen out of style lately.