Hi,
In my 1900-remodeled 1850's house the bright Georgia pine trim was supplemented with painted sash. They were apparently a very dark grey, although it could also have been a very dark graining (there is very fine alligatoring on that layer so it may have been a colored shellac)
I am stripping the woodwork and refinishing, and using paint for the sash. I chose a color that sort of harmonizes with the pine, sort of a mustard/terra cotta. This sheme is being carried out throughout the house as I redo the sash, and it looks pretty good.
So, entertain the idea of either a faux in the color of the trim, or a paint, and I think any amount of contrast would be acceptable.
Casey

We have a combo of both stained wood trim and painted. We basically kept the stained as is, but stained some new baseshoe molding to match. You can get a custom stain made to match existing wood work. The wood that was already painted out we just freshened with some bright white paint.

It's personal preference. All the new houses have completely painted trim so the dark wood is a nice change.