ΔE 12.4, fair: the same colour family, but not a straight swap. Gutrippa Flesh is noticeably darker than Matt Light Green. They are different kinds of paint: AMMO by Mig Matt Light Green is an ink, glaze or transparent 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 than Matt Light Green. They are different kinds of paint.
The same difference applies the other way round: Matt Light Green is noticeably lighter.
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 Matt Light Green on the colour wheel See Gutrippa Flesh on the colour wheel
All matches: Matt Light Green equivalents · Gutrippa Flesh equivalents