Tamiya M1046 HUMVEE paint question

I’m doing the desert paint and I’m wondering if the Tamiya instructions are correct. Shouldn’t the drive-train and undercarriage be completely FS33531? I couldn’t find any pictures, but I know someone here will know the answer to my question.

The undersides should be Flat Black

It actually depends. If it is a new-build HMMWV, the underside would be black. If it is an older vehicle that started life in NATO camo and was repainted sand, the underside would usually also be sand from being painted with the rest of the vehicle. So either is correct.

That muddies things a bit. Lol. Thanks for the help, guys. It’s much appreciated.