Death Guard Green vs Olive Green (USAF)

How close are they?

ΔE 19.8, loose: different enough that you should pick on purpose. Olive Green (USAF) is a little darker, much more muted than Death Guard Green.

Can I use Olive Green (USAF) instead of Death Guard Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Olive Green (USAF) is a little darker, much more muted than Death Guard Green.

Can I use Death Guard Green instead of Olive Green (USAF)?

The same difference applies the other way round: Death Guard Green is a little lighter, much more saturated.

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.