ΔE 11.2, fair: the same colour family, but not a straight swap. Terminatus Stone is noticeably darker, cooler than Matt Beige. They are different kinds of paint: AMMO by Mig Matt Beige is an ink, glaze or transparent paint and Citadel Terminatus Stone is an opaque base/layer 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 11). Terminatus Stone is noticeably darker, cooler than Matt Beige. They are different kinds of paint.
The same difference applies the other way round: Matt Beige is noticeably lighter, 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 Beige on the colour wheel See Terminatus Stone on the colour wheel
All matches: Matt Beige equivalents · Terminatus Stone equivalents