The Discoprise isn't nearly as dark and metallic as people seem to think it is. Whenever it's shown in more direct lighting, you can really see her true colours.What King Daniel said. Also, those weird windows along the saucer's edge.
But most importantly: They look chrome & shiny! The Discoprise has that NX-01 blackness, like a ship from the alien-franchise.

I duplicated this look as best I could when I built a model of her and I think I did a pretty good job.

