I have seen it done.
Good luck with your project!

Yes, it was often done in colonials. I was so tired of people painting trim white (to make it Pop! as they would say on HGTV) that I purposely did not.

All of our walls are shades of white, and the trim is shades of cream (one exception, our DR has a wall of windows with an olive trim) So I didn't go wild but the trim is clearly darker. I really like it.

It all depends on the architectural character of your house and the impact of the size and design of the trim (ceiling, windows, chair rail, base, etc) have on the aesthetics of your interiors.

Painting the trim darker than the walls will always call attention to the trim members and create a strong contrast between walls and trim. This may be good or bad, depending on the architectural character and the actual hues/values involved.

Making trim and walls similar in hue and/or value will unify and downplay the contrast.

You can always try a few test colors to look at in natural and artifical light to judge the effect.

Good luck!

I love a taupe color trim with lighter walls. It is a very historical look. It can be very pretty!