See? Similar sizes, different shades...I'm not picky about it when its an outside battle of hundreds of troops getting things thrown at them, but I want to have a more uniform look for the tabletop.
STEP 1: I made a bath of soap or detergent and warm water and poured the hapless victims in because plastics usually have residue from a mold release spray when they come outa the factory. I let them sit a little while while I played Star Wars Battlefront.
STEP 2: After they were rinsed off and dried (I wrapped them in paper towels and then I used a hairdryer to blow off the water) I took them outside. I had bought Krylon Fusion Cammo. Krylon Fusion bonds to plastic at the molecular level, and I had great results from a can of Fusion blue when I was doing my Cobra Troops. I'm using Olive for the green soldiers, and Khaki for the tan soldiers.
STEP 3: I layed the soldiers face down and did a spray towards the top of thier helmets, and then went to thier feet side and sprayed again. I find that this helps get paint in some of the crevaces that you can't hit by just spraying from one side. After I did that to the Tan, I hit the Green troops with olive. When I was done with that I flipped the Tans over and hit them from both sides, then flipped over the Green and hit them from both sides. I wasn't too worried if I missed a spot here and there, if the majority of the figure is one color it's really not that noticeable when you have a squad of ten soldiers together.