We like the clad windows - aluminum or vinyl on the exterior with the wood interior. This gives the flexibility to stain or paint the interior depending upon the décor. You do need to paint the interior at some point when you paint the rest of the room, but that is no big deal. I don't like a white, white vinyl window (or brown or whatever) that does not match up with the remainder of the trim in a room.

I would love to use aluminum clad wooden windows for that. It will give you that rustic look in your cottage.