Our coop is dark on the outside but has white interior walls for the hen house and also light colored nest boxes and a light colored roost. Research before I built the coop suggested that the chickens needed a distinct difference between night and day, also that they don't see well in the dark, so it seemed to me that the best design was one that included a light interior. The light colors will help with all of the above. Here are some pictures:
The exterior of the coop:
You can see that the exterior stain is quite a dark color, almost mahogany colored (well, except for the door, which is cherry, LOL!).
The interior of the hen house:
On the other hand, you can see that the interior walls are white, the linoleum is tan, sort of, and the roost is an odd pastel 'puce'-like color (it was an 'oops' can of paint!). The nest boxes are a very light tan color just about the exact shade of new pine shavings, they go well with the linoleum, LOL. Of course, now with actual pine shavings on the floor, you can hardly see the linoleum at all -- so much for trying to have any kind of color scheme!
Does that help? I figured having a dark outside but a light inside was the best compromise.
Whitewater