Just some more data re this skin.
Il2 has this skinned as White 01 as does Osprey books. However I would ask any potential skinner to look at the picture below

This is quite a famous picture but this one was also in Seidls book "Stalins Eagles". This book actually includes a foreword by Popkov himself plus the colour plate in my original posting above
Both the plate and the above picture refer to Yellow 01.
However I would ask any skinner to look closely at the black & white picture above. It is clear that the "0" is a different tone to the white leader stripes on Popkovs Lavochkin. However look also at the border to the Star.
The colour plate picks out the star with a well defined red border. This is not so in the picture. Further the colour of the stars main border is not as white as the leader stripes behind it. I believe that the white border to the star may have been over painted Yellow.
This would now begin to make some sense.
The original camo would have been over painted locally by the white leader stripes and may have recieved a light lime wash in the winter of 44 (fading the original scheme).
The star and the 01 may then have been picked out in yellow properly define the star and to further define Popkovs aircraft.
His kill stars added and updated as more were aquired.
I am certain in my own mind that the 01 was indeed yellow, the same yellow as found on the Guards insignia. Whether the star was bordered yellow or not I leave upto the skinner. The practice was not unknown as recorded in Pilawskii's book (page 210)