ΔE 12.2, fair: the same colour family, but not a straight swap. Gutrippa Flesh is noticeably darker, more saturated than Grass Green. They are different kinds of paint: AK Interactive Grass Green is an opaque base/layer paint and Citadel Gutrippa Flesh is a one-coat contrast-style paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Gutrippa Flesh is noticeably darker, more saturated than Grass Green. They are different kinds of paint.
The same difference applies the other way round: Grass Green is noticeably lighter, 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 Grass Green on the colour wheel See Gutrippa Flesh on the colour wheel
All matches: Grass Green equivalents · Gutrippa Flesh equivalents