Hi there - here are some attempts at US armour -
The M4A3(late) in the middle is
GW Deathworld Forest, the rest are Vallejo Brown Violet, however the difference doesn't come across very well via the wonders of my phone camera. Brown Violet is better, I've come to the conclusion 4 Vallejo paints are required if (like me) you already have a large
GW paint collection - Brown Violet, Khaki, Green Grey and US Field Drab. The rest
GW can do a decent job of.
I've also experimented with Micro Sol and Set, but I haven't done a very good, they all still look like transfers, more work required. Still have to try camo nets, foliage, Culin cutters, stowage and all that.
Any C&C welcome, enjoy dudes