Think of introducing a contrast to the white - black being very contrasting, white not being a contrast and soft grey being somewhere in between (but possibly not quite enough, in which case you may need to go for darker shades of grey) . The analogy might be framing a picture or piece of art- If the canvas is really white, you wouldn't choose a white frame. Or putting on eye makeup- if you choose to put a colour on your lids and don't include eyeliner or mascara, your eyes will lack definition ! What colour is the roof ? Also ,have you chosen the white of the exterior yet because these two factors can help in your decision process.

if you are speaking of the eaves ie the ceiling under the overhanging roof all around: paint white and the fascia and barge boards which are the backing behind the gutters and the trim at the end of the gables: consider grey (similar to roof?) so that you will have large expense of white with medium amounts of grey with black highlights

I rather like the look of dark ie black or charcoal fascia.