Right out of the factory I don't think the light green looks right either but, it might be a future result........ considering the following.
Just remember, (whatever green you use ) weathering will alter the final color. The paint can be faded or tainted from the whitewash applied from any winter configuration. In other words, a faded look could also be left over residue from a winter whitewash or a heavy accumulation of dust in combination with the bleaching effects of the sun. Some tanks didn't last a day and yet there were those that were repeatedly repaired and put back into action.
Also, WWII russian paint wasn't too tight on quality control. A tank painted at one factory could be a different shade or hue from a vehicle produced at a different plant. Also, (mentioned above) consider a machine damaged in action and repaired/painted at depot or rear echelon level; or even painted at all considering the imminent situation, again, an opportunity for a different variation in color.
Armor desperately needed to stop the enemy doesn't need paint to be a beauty to their desperate comrades fighting for their lives. An example of extreme need would be at Stalingrad. The T-34s were coming out of the factory with a crew at the door and headed straight into battle in primer red and in some cases no paint at all.
Any russian WWII armor that I would build would incorporate these conclusions; for as you all know, I just won't build a pretty tank.