What would be a good color in the Tamiya acrylic line for soviet armor of this era?

I'm about to paint my T-34 with Dark Green, but I think its too dark. Anyway I'm going to do it and see how it comes out.

As Lee has already guessed, a truly dark green doesn't look too good in scale. And 4BO can be very dark indeed - Aberdeen's KV-1 was delivered in a colour approximating to FS 34052.

How about using NATO Green with a dark wash?

It's my understanding that there's some controversy about it, but most Russian armor came off the assembly line in a shockingly GREEN green. (I can't remember the chemistry behind it, but apparently the paint was a simple formula that produced a vibrant shade.) I don't know what's available in Tamiya's line to match it, but I know Testor's Model Master Acrylics line has a Russian Armor Green specially made. Once you weather it, it looks good.