I don't think I understand that sentence. Are you saying that the USAREUR Sand color was not matched to FS595? If so, I would guess it was a German paint; in that case, it can either have been a custom mixed color, or a standard RAL color. Or what do you mean by "different type of paint"?
The only WWII Sand I have to judge visually is the very pink Sand 26 sample from Archer's book on USAAC colors. There seems to be no FS color like it, but RAL 3012 Beige Red looks *very* close. However 30279 also has a pink tone, and was already mentioned as a possible candidate for the sand color?
I just don't notice anything pinkish about the sand color in any of the images I've found so far, though, but that could be due to the reproduction, of course. Comparing the pictures to pictures of MERDC vehicles, where the sand color is most likely 30277, I'd say the color looks similar.
-Lasse