Ork Flesh vs Armor Green

How close are they?

ΔE 6.4, close: similar, with a visible difference side by side. Armor Green is more muted, cooler than Ork Flesh.

Can I use Armor Green instead of Ork Flesh?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Armor Green is more muted, cooler than Ork Flesh.

Can I use Ork Flesh instead of Armor Green?

The same difference applies the other way round: Ork Flesh is more saturated, warmer.

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.