Hey Sal,
My guess is that it was 4-BO-green. When it was ''erbeuted'' they sprayed large german crosses and a swastika on it for identification. On the photo the KV looked ''fresh'', so no panzer gray paint would be added. The captured tanks were send to the back often to be refitted and oversprayed (mostely in the Daimler factory and some unknown servicepoints at the baltic country's)
In 1943 a major factory in Kharkov was captured by the second ss division
"das reigh'' that was producing T-34. A lot of colorfull vehicles were ''made'' there. Currently i am making a T-34/76 from that factory that served in ''operation citadel'' in the ''under a differend flag'' campaign. Maybe you can do some inspiration there.
Regards and happy building,
Remco