Wings, I would go wit painting them all over with codex grey (Now called Dawnstone I think), then simply painting the flat tops of the feathers with your standard white, leaving grey in the crevices to shade.
I don't personally, so I can't vouch for the end result, but I suppose you could add a bit of codex grey into the white to tone it down a bit when painting the feathers, allowing for a white edge highlight along the feathers edge. Similarly, you could add a bit abbadon black to the codex grey basecoat to add more shade. however, as I said before, I can't vouch for how that experimentation would turn out.
How about doing a bit of blending from a white feather tip through yellow and orange to a crimson feather root...