new to forum,weathering ques.

Can I guess the base color is a medium gray? Try a darker gray but not straight black. this will bring out the details without too much contrast. Coated in Future? Use a oil paint based wash but careful not to over work this, as the thinner is powerful stuff. Or just use standard enamel hobby paint. After this has cured a few days then select 'pin washes' in a darker color near black can be applied in thinned acrylic paint. Avoid tap water, demineralized water is better (free of minerals that will stain when dry), I prefer isopropyl rubbing alcohol.

May the force be with your modeling... always.

Thanks for responding, nice to meetcha, I'll get right to it.  The ship has 5 under coats from black to grey to a sickly rust green just under the white, all enamel.  Also "panel lines" & corners were pre shaded.  I maske off many small geometric shapes on the hull for markings.  This is my first paint job of this size & I think I got what I was going for, as far as something much deeper than an even white on plastic.  As I'm thing washes I cant shake the idea of a odd color, something almost "organic".  Mossy or rusty or who knows.  Am I onto something or way off?  Plus, I've only used a sludge wash in the past(hence the future).  Any way, thanks again,  any input would be valuable.

Maybe I should be thinking of a filter instead of a wash at this point.