Mike Mackowski, and aerospace engineer, has a site called Space in miniature (SIM) - http://www.inficad.com/~mjmackowski/
He has a number of booklets that " are designed to provide the serious "real space" modeler with the scale data and modeling information that cannot be found anywhere else."
In SIM#4, dedicated to Soviet Spacecraft, he writes that he glues on crinkled aluminum foil to simulate the blanket and then paints it with "a mix of 11 parts Pactra X-5 Leaf Green and 10 parts X-43 Turquoise, producing a flat jade green."
I highly recommend these books to anyone who wants to get the details correct. Unfortunately only SIM 3 and the newly released SIM 6 is still in book form. The rest are photocopies. But still worth getting. Good luck.