ΔE 11.7, fair: the same colour family, but not a straight swap. Waaagh! Flesh is a little darker, more muted, cooler than Space Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Waaagh! Flesh is a little darker, more muted, cooler than Space Green.
The same difference applies the other way round: Space Green 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 Space Green on the colour wheel See Waaagh! Flesh on the colour wheel
All matches: Space Green equivalents · Waaagh! Flesh equivalents