This photo demonstrates a lot of the problems with trying to judge "accurate" colors from WW2 color photographs. Tonal shifts from the film/developing process, lighting, dust, etc. are all in play in this one.
It has all the characteristics of a late Jagdpanther in relation to the mantlet and barrel, which means it would've most likely been finished in a basecoat of Olivegrun and the dark yellow added over that along with the possibility of additional red-brown.
FWIW, there haven't been any documented cases of actual vehicles leaving the factory in '45 with the panzergray applied. The order in place for a short period allowed for the use of panzer gray "IF" they had it still on hand "AND" they didn't have sufficient stocks of Olivegrun and/or dark yellow.