That's a lovely home!

The tan/beige idea would be worth pursuing and I can tell ya why. It would be more visually interesting than the light gray. Light gray will match and will work just fine if you really want to go that route, but the tan/beige option would be far more complex. That choice would be a bridge color from the brick to the roof, it'd be an additional color *layer* visually.

A tan/beige with a strong, grayed edge would be something like BenM's Quincy Tan, Huntington Beige, Yorkshire Tan and I know there are several others but I can' think of them right now. Remember you need to test and choose colors that look a little darker on the than chip than you'd ultimately like to end up with on the trim -- natural light exterior is fuller, more robust, and intense and that will strip color, wash it out. So it's a good idea to choose exterior paint colors that are robust and full too.

As far as shutters with a tan/beige, you have many options. A range of uber dark interesting reds, charcoal instead of black, *black* with echoes of undertones from purple to green to navy if you want.

Could even choose a tan/beige that is more like khaki and leans a bit green and then choose a deep olive green for the shutters.

You have great color bones to work with and so many color options/color schemes will work. Just need to determine what it is you really want the resulting color scheme to *say* about you and your house.