That's a loaded question! :) I'm guessing you're asking what to use as a BASE color for your hull, since it is a very heavily weathered and patched up ship, with multitudes of primer greys, oxidized reds, and a spectrum of whites. Stay away from pure white, obviously, because it will transform it from model kit to *toy* in appearance. On the Falcon's I've built, I used Pactra flat paints-- ok, it's been a few years-- but the base coat, if I remember correctly is like a ghost or camoflage grey. It is a very light grey, that I'm sure of. When photographed, it still looked like a dingy white. The reason I used a flat was it makes doing weathering much easier. Washes and top colors tend to blend into the base coat better than if it is glossy. Besides, the Falcon is an old beater of a ship. No gloss is left on her paint job.
Biggest key to a good looking Falcon: Patience, and study of reference photos.
Tamiya has a very nice looking flat off-whitish/grey that is very smooth in texture when sprayed.