I would definitely suggest painting the lower skirting/rocker panels the same color as the car as it makes the car look lower, in my opinion. As far as the trim that encircles the car, it's up to you. I think it can look good painted the same color as the car, but can also look good black.

When you see a black BMW, everything is essentially the same color and it looks good so it should work with other colors, right?