ΔE 7.9, close: similar, with a visible difference side by side. Gnome Cheeks is a little darker, more muted than Matt Earth. They are different kinds of paint: AMMO by Mig Matt Earth is an ink, glaze or transparent paint and Army Painter Gnome Cheeks 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 8). Gnome Cheeks is a little darker, more muted than Matt Earth. They are different kinds of paint.
The same difference applies the other way round: Matt Earth is a little lighter, more saturated.
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 Gnome Cheeks on the colour wheel
All matches: Matt Earth equivalents · Gnome Cheeks equivalents