ΔE 8.9, close: similar, with a visible difference side by side. Forest Skin is a little lighter than Catachan Flesh.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Forest Skin is a little lighter than Catachan Flesh.
The same difference applies the other way round: Catachan Flesh is a little darker.
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 Catachan Flesh on the colour wheel See Forest Skin on the colour wheel
All matches: Catachan Flesh equivalents · Forest Skin equivalents