Reference pictures

Guy Golsteyn
All these pictures were taken at the same GP F1, the 1953 Silverstone GP, won by Alberto Ascari. It's rare to find so many color pictures of this period, so I'm pretty pleased to have them. But at the same time there is something puzzling me: the wire wheels of the Ferraris (not just Ascari's car) seem to be some kind of green/blue instead of the standard metallic color. At first I thought it was an error of the colors in 1 picture, but I see this on all color pictures. I have never seen this before. Anyone any idea what this is about?

Also, I noticed that the race number '5' is black on a white roundel, but only on the nose. The rear shows white numbers '5' without roundels. This is where the kit went wrong, because there are only black numbers on white roundels in the kit. I will have to correct this error...