Ordic Olive vs Goblin Green

How close are they?

ΔE 23.8, loose: different enough that you should pick on purpose. Goblin Green is noticeably lighter, much more saturated than Ordic Olive.

Can I use Goblin Green instead of Ordic Olive?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Goblin Green is noticeably lighter, much more saturated than Ordic Olive.

Can I use Ordic Olive instead of Goblin Green?

The same difference applies the other way round: Ordic Olive is noticeably darker, much 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.