ΔE 11.9, fair: the same colour family, but not a straight swap. Drain Life is more saturated than Guilliman Flesh.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Drain Life is more saturated than Guilliman Flesh.
The same difference applies the other way round: Guilliman Flesh is more muted.
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 Guilliman Flesh on the colour wheel See Drain Life on the colour wheel
All matches: Guilliman Flesh equivalents · Drain Life equivalents