It looks like a good idea to me, I think the charcoal colour would be best because it'll blend in with the grey feathers & look less tacky.

But if u do want colour that'll standout but still match Nelly the gold & lilac would works quite well. the gold will match the crown (I think thats what its called) & the lilac will match the white on the wings.

But I still think the charcoal is the way to go.