Waaagh! Flesh vs Green Oxide

How close are they?

ΔE 16.8, loose: different enough that you should pick on purpose. Green Oxide is noticeably lighter, cooler than Waaagh! Flesh.

Can I use Green Oxide instead of Waaagh! Flesh?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Green Oxide is noticeably lighter, cooler than Waaagh! Flesh.

Can I use Waaagh! Flesh instead of Green Oxide?

The same difference applies the other way round: Waaagh! Flesh is noticeably darker, 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.