In Germany, we spray painted our 60's with green, brown and black. 3/33 armor / 3rd AD. There were variations of this unit to unit (pattern wise). Stateside, there were sections of light gray in the camo scheme, ( Ft. Carson, 4th ID I believe). Our Rise Passive were delivered with a different type of track than the older tanks. This "new" type had individual replaceable pads that required an extra bolt to secure the pad to the track block. This was intended to ease the maintenance chore of breaking the track and replacing a whole track block when the rubber chunked off. Color wise, no difference. The end connectors, sprocket and center guides should show bare metal wear, unless your tank has been sitting in the motor pool for a while. Rear Grille door fins should be a smoky rich flat black, (diesel exhaust).
Can't wait to see your finished product, good luck,
Steve