Matthew,
By the color profiles you provided I assume you are talking about Muncheberg's "White 12" in Sicily. If so, it is a tricky question, for a couple of reasons. First, questioning Airfix' color schemes is perfectly valid - I am building their 1/48 E-4 right now, so don't ask me how I know... Second, there is still uncertainty how this aircraft was painted. I was able to find an old forum discussing this very plane, this might be of help to you: https://ww2aircraft.net/forum/threads/j-muencheberg-bf-109e-7-white-12-camo-color.30221/
The only image I could find won't help with the colors, but at least can give you an idea of how the mottling was applied. More interesting though is that it shows a white "1" instead of the white band.
As to how to do the mottling, I can only suggest using an airbrush with a fine needle, heavily thinned paint and low-ish air pressure. Personally I would stay away from water-based acrylics (like Vallejo etc.) for that and instead use laquer paints like MRP, or Tamiya / Gunze paints thinned with levelling thinner. And practice on a scrap piece of plastic first to get the air pressure right 🙂
Hope that helps,
Boris
1 attached image. Click to enlarge.
