I say this in the kindest we possible... start over. I would strip it and start again.

Look at military colors that fit the palette you going for. Camo gray or aircraft gray rather than white. Nato green, OD green, or marines green rather than crayola green. Gunship gray rather than gunmetal. I think you might find it gives you a more realistic finish. Then dry brush them down with the base color. Then a wash with a bit of earth brown and black.

Again not bagging on you, we all had to practice to learn what works. I can't tell you how many kits trashed when I was a kid starting at this hobby.

Keep at it!