I think you should start fiddling around with the digital image you have, just to try out some colours. Or print it on paper and colour them that way.
The Bone white with golden accents will ofcourse work, but I can understand if you want something different. BFG styled ships often end up in a more "muted" colours, war-torn, ages old look, you know what I mean. With FSA you often see the morge bright models. Withing BFG only Eldar and Tau end up like that with some. It is just the universe they fly in.
Paint them in a BFG style the BFG following will immediate recognize them and love it. Paint it in a more non-bfg way you might perhaps find more customers (as they eye is caught differently) outside the BFG community.
The model itself is great but non-bfg'ers will at a first glance always tell it is bfg. Ofcourse.
The rounded surfaces on the model scream for a good colouring.
