ΔE 7.4, close: similar, with a visible difference side by side. Ratling Grime is more muted, cooler than Sand Grey. They are different kinds of paint: AMMO by Mig Sand Grey is an opaque base/layer paint and Citadel Ratling Grime is a one-coat contrast-style 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 7). Ratling Grime is more muted, cooler than Sand Grey. They are different kinds of paint.
The same difference applies the other way round: Sand Grey is more saturated, 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 Sand Grey on the colour wheel See Ratling Grime on the colour wheel
All matches: Sand Grey equivalents · Ratling Grime equivalents