The T-34 at Kursk was an all over green. Ther were camouflaged versions but they were a very small number
Here is a link to some photos to give you a good idea.
https://blog.tiger-tank.com/incombat/soviet-tanks-kursk/
In contrast, the German forces had learned much about tank camouflage strangley from the Russians since 1941 and in February 1943 changed the base colour of their vehicles to a colour called Dunkelgelb nack Muster, or translates, Dark Yellow after pattern. This colour was sent to the RAL colour people along with a request that it was designated as RAL 7028. Now, this did not happen to this colour shade.
Now, the original Dunkelgelb nach Muster was used from February '43 to August '43 when it was changed after much feedback from the front.
As a german vehicle owner and restorer I have these correct shades. Here are the originals, being matched to AK's "Real Color"
Original Dunkelgelb Nack Muster. Dropped from service August 1943 being too bright.
What went into the RAL colour set as RAL 7028 was this one from August 1943.
May 1944 saw RAL 7028 change again. I don't know the reason why as it is a very effective base coat when combined with RAL 6003 and RAL 8017.
The above base colour would have been seen on new German vehicles in Normandy.
The last colour came into use during Christmas/new year '44/45. This saw a huge change in vehicle colours with the base coat being changed to RAL 6003.
Usage during Kursk.
All new vehicles from February 1943 were sent out in the Dunkelgelb Nach Muster base coat from factories. maintance companies would apply disruptive camouflage locally delending on operational theatre and conditions. This was mostly RAL 6003 Green. Armour etc already in theatre and painted the orogonal Dark Grey RAL 7021 were painted with disruptive pattern of Dunkelgelb Nach Muster.
Panther D tanks would have an all over DNM paint job with RAL 6003 Green disruptive pattern. They were the new boys on the block and their design was taken from the T-34. Hitler delayed Kursk to allow these to be put in place and used.
When Germany invaded in 1941, the T-34 and KV-1 came as a huge shock and very nasty suprise to the Germans and as the Tiger I was well into development there was no real way the new information got from captured T-34 tanks could be incorporated (mainly sloped armour) so the Panzer V project to incoporate the new information was started and the first D production models were rushed into combat at Kursk. It met with not much success due to testing etc being cut short and many Panthers suffered fires, breakdowns etc.
It's sucess was the 75mm main gun having much the same success against the T-34 tanks as the Tiger I 88 L/56 with a general one hit kill. the Panther sloped frontal and turret armour proved a success too.
The faults of the Panther were very quickly identified and fixed and the Panther quickly became one of the most feared armoured vehicles by the allies, who would press captured working ones into use.
For accurate painting of German armour during Kursk I would recommend Vallejo.
DNM 71.025
RAL 6003 71.092
RAL 8017 71.041
Russian T-34 base colour 4BO Vallejo 71.017
If you want to do a 3 tone camoflage one, then
Russian 6k disruptive 71.282
Russian disruptive 7k Vallejo 71.283