ΔE 4.0, very close: most people won’t see a difference side by side. Our swatches for the two are almost the same. They are different kinds of paint: AK Interactive Grim Brown is an opaque base/layer paint and Army Painter Matt Black Primer is a technical paint or medium, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 4). The swatches are almost the same. They are different kinds of paint.
The same difference applies the other way round.
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 Grim Brown on the colour wheel See Matt Black Primer on the colour wheel
All matches: Grim Brown equivalents · Matt Black Primer equivalents