Here is the "muddy brown"... A mix between RLM79 and Middle Stone
I found some infos in my docs: "colori ufficialmente impiegati dall'aviazione italiana 1916-1943"
It looks like "Giallo Mimetico 4" (more darker than Giallo Mimetico 3)
I wanted to do more darker than Giallo Mimetico 3... I hope it's to close to the famous "muddy brown" described in the article...
Green blotches tomorrow...