Well the real Galactica was simply white shot with harsh lighting to make the shadows. To simulate this you have a few options.
Follow the directions in the kit - and pre-shade the thing by painting it black and then come back with many light coats of white until it gets to the shade you want.
or
Paint it your favorite color of white - off white and then give it a dark gray to black wash.
I painted mine Tamiya AS-20 insignia white, and then washed in Dark gray. I don't have any decent pics since it still being built but I'm pretty happy with the color. "almost" white, with darker areas in the detailing. I am kinda angry at myself though - decaling and scotch don't mix... I messed up a bunch of the decals by not waiting long enough for them to set then handling the model to apply more decals... Mistake. I may just look for a red paint that matches and paint them in...
Jedi Dade