Jeff,
welcome! i see the gang has been much help.
i'll take this easy one.
if you are going to acrylic,
the 'tan' is really "dunkelgelb" (dark yellow) and Tamiya XF-60 is the common choice.
the reddish color is usually XF-64 (red brown)
and the green XF-61 (dark green)
typically, we wash the living heck out of (or on to!) armor,
so between giving yourself leeway for washes (which will darken the colors)
and some wiggle room for 'scale effect" you may want to lighten these around 20%
using white or tan to knock them down a bit.
some folks use them straight. there is a LOT of leeway, so do what pleases you.
you will find there will be folks who do the same thing, and folks who don't.
you will likely want to shoot the dark yellow base coat over the whole thing then apply the red & green.
that is something most here would agree on.
dirty pool, wipw!
i like that!