That's the thing of course, they are brand new... Maybe you could try something more subtle than weathering: Paint first in a very very light grey, then overspray with pure white. The overspray should (I say should!) rest on the raised areas (such as strap on boosters and the like). For larger areas, maybe the same paints but spraying the white away from divisions, panel lines, ..., towards the center of the panels. You should end up with very bright panels that are lightly 'shaded' towards the joints...
Just a idea... Never tried it...