ΔE 9.7, close: similar, with a visible difference side by side. Plague Green is a little lighter, warmer than Ork Flesh.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Plague Green is a little lighter, warmer than Ork Flesh.
The same difference applies the other way round: Ork Flesh is a little darker, cooler.
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.
See Ork Flesh on the colour wheel See Plague Green on the colour wheel
All matches: Ork Flesh equivalents · Plague Green equivalents