Hi Massimo,
... yellow (yg) looks more reddish than it, while it should be not reddish at all. The defintion of 'yellow' instead of 'brown' , 'Khaki', 'Ochre', 'Sand' etc is a bit strange for a so dark color, probably it is hard to be defined in other ways.
"Yellow" is actually the only puzzling color with no Army equivalent. IMHO, it doesn't have any connections with postwar colors. Its name could be explained by the fact that all four terms you are suggesting had already been reserved for other colors:
-There were already two "brown" colors - dark brown 6K and light brown 7K
-In Russian "Khaki" is equivalent to "zashchitnaya" ie. olive green
-"Ochre" was most commonly used pigment
-"Sand" was used for 7K
Regards,
KL
