Revisiting this thread, some points.
316 Squadron swapped from Hurricane to Spitfire in November 1941
http://en.wikipedia.org/wiki/No._316_Polish_Fighter_SquadronZ2585 was a Hurricane Mk.IIA, built by Hawkers before April 1941 and serving with 56 and 316 Squadrons before being sent to Russia on 11 December 1941.
the 316 Sq page linked
http://polishsquadronsremembered.com/316/41/1941_hurricane_pics.htmlMix group of airmen and erks in front of Hurricane Mk IIA SZ-H, Z2506 late 1941
and
Both show planes that have been repainted in Day Fighter Scheme, with a low contrast, suggesting use of a mixed grey.
While 42/Z2585 does not appear like this, I think this is most likely in DFS, with some large fresh patches of RAF Dark Green used to overpaint RAF MArkings and codes.
note in this image
how the tailplanes, which are getting light off the snow, are darker than the sky band.
also note the spinner vs the wing root, which should be really bright if sky, from light reflected off snow.
The patch behind the '42' on the port side is strange, fresh Ocean Grey possibly?
There are other factors, strange lighting, due low sun and cloud, note the light is very diffuse, with no hard shadows, and possibly a coat of ice over much of the plane, giving a gloss effect.
As I have pointed out before, Lend Lease Aircraft being
delivered with original national markings, be it RAF or US, are the exceptions. Odd shoddy overpainting yes, but not VVS overpainting.
One area of confusing maybe the oft reproduced aircraft at NII VVS, which were sample aircraft, and repainted in a rush, or not at all, and these would have VVS overpainted markings.
Main deliveries, eg photos from Abadan and ALSIB show application of Red Star
before delivery.
the other exceptions would be aircraft handed over by the RAF in Soviet Union, eg 151 wing and some PR aircraft. In case of 151 wing I wonder if RAF paints were used there as well, but are fresh/different batch so appear different.
Hope of interest.