ΔE 10.7, fair: the same colour family, but not a straight swap. Briar Queen Chill is a little darker, cooler than Wolf Grey. They are different kinds of paint: AMMO by Mig Wolf Grey is an opaque base/layer paint and Citadel Briar Queen Chill is a one-coat contrast-style 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). Briar Queen Chill is a little darker, cooler than Wolf Grey. They are different kinds of paint.
The same difference applies the other way round: Wolf Grey is a little 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 Wolf Grey on the colour wheel See Briar Queen Chill on the colour wheel
All matches: Wolf Grey equivalents · Briar Queen Chill equivalents