ΔE 16.7, loose: different enough that you should pick on purpose. Gengis Khaki is a little darker, more muted, cooler than Catachan Flesh.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Gengis Khaki is a little darker, more muted, cooler than Catachan Flesh.
The same difference applies the other way round: Catachan Flesh is a little lighter, 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.
See Catachan Flesh on the colour wheel See Gengis Khaki on the colour wheel
All matches: Catachan Flesh equivalents · Gengis Khaki equivalents