I have a light gray house. I want to change the color of my shutters from a blue/gray to maybe a charcoal gray. She the door match the shutters and what color trim should I have

Black shutters and a black door would be very dramatic. White would be clean but not very interesting.

I suggest you make the decision using the color of your roof. Many colors will blend with your gray, but may not blend with your roof color(s).

A dark color would be best. White would look good too, but as a commentor stated it is a bit bland. We purchase dark, wood grained polyurethane exterior shutters for our design projects. They look great, can be painted any color and best of all do not deteriorate like real wood exterior shutters. Good luck http://www.owtraditions.com