Hi, Tim!
I'm no expert on Soviet armor, but I've heard that you really can't go wrong painting 'em! In WWII, the Soviets were painting (or not!) their vehicles with anything available, mixing pigments with water, kerosene, gasoline, even engine oil. So you can imagine the mad variety of greens you could get!
The Tamiya enamel or acrylic Dark Green XF-61 is a good place to start.
I haven't gotten the latest issue of FSM yet (takes a month for my copy to reach Japan!), but I understand there's a good story about a T-34 build. You might want to check and see what the painting recommendations are there.
Happy modeling!