Paratrooper Tan vs Dark Beige

How close are they?

ΔE 16.6, loose: different enough that you should pick on purpose. Dark Beige is noticeably darker, more saturated than Paratrooper Tan.

Can I use Dark Beige instead of Paratrooper Tan?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Dark Beige is noticeably darker, more saturated than Paratrooper Tan.

Can I use Paratrooper Tan instead of Dark Beige?

The same difference applies the other way round: Paratrooper Tan is noticeably lighter, more muted.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.