As far as I know, the Marder SPAT conversions weren't produced until early in 1942, so being painted in grey would mean that this was one of the first to go into service, before the changeover to dunkelgelb as the base colour for German AFVs. There were about 350 built, in total.
I've used a new colour as the basic grey this time: VMA 72.128 Grey Violet, which is a warmer and slightly darker grey than VMA 71052 German Grey, and just a fraction lighter than my current favourite for Panzer Grey, VMC 866 Grey Green.
The construction instructions included with the kit are quite incomplete when it comes to this variant. I had to make a guess as to where some parts were meant to go after looking at some pictures on the internet. I think I got it pretty right.