ΔE 9.5, close: similar, with a visible difference side by side. Kislev Flesh is a little lighter, more saturated, cooler than Matt Earth. They are different kinds of paint: AMMO by Mig Matt Earth is an ink, glaze or transparent paint and Citadel Kislev Flesh is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Kislev Flesh is a little lighter, more saturated, cooler than Matt Earth. They are different kinds of paint.
The same difference applies the other way round: Matt Earth is a little darker, more muted, 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 Matt Earth on the colour wheel See Kislev Flesh on the colour wheel
All matches: Matt Earth equivalents · Kislev Flesh equivalents