All Stuarts have had a FoW US Armour spray base over grey polyurethane primer, a GW Badab Black wash followed by a heavy Vallejo Brown Violet drybrush. I've only just done the hulls half an hour ago and below is a pic of their current progress.
The tank on the right is how I'm going to paint them all hopefully, perhaps slightly lighter in tone though as I think it looks too much like a British tank rather than American.
Yesterday I received 160 rare earth magnets to magnetise every one of my turreted vehicles as I've been noticing more and more wear/paint damage to my Cromwells and a few other tanks. These Stuarts have all had their turrets and hulls magnetised to not only to protect their paint work but also to protect the phenomenally fragile .30 Cal MGs and their tiny main gun barrels.