We have a 1920s craftsman home with similar wood trim (and built-ins). California Paints has a great set of period colors, if you want to go that route. Otherwise, I'd agree that anything more vibrant will really brighten the space and make it feel less dated. You could do a slightly lighter version of the color above the chair rail and it would look great.

Personally, I'd stay away from the darker paint colors, but that's just my preference.

That wood trim makes me think Arts & Crafts style (the original, old kind - not the new $1.5 "bungalow" kind). Those houses had lots of wood trim and usually rich darker paint colors. Burgundy, mossy green, custard yellow. There's a magazine called American Bungalow, and I'm sure many others, which might be a good starting point.

Please spam me with ideas for decorating (including wall paint colors) around wood trim. Looks a bit like this but darker -- hard to describe exactly but it feels less dated than the picture. I do not want to paint over it. Floors are also hardwood (standard style, not like the floors in the pic) and a similar but not identical color to the trim. Walls are currently all off-white. Thanks!