ΔE 12.9, fair: the same colour family, but not a straight swap. Bright Slate Grey is noticeably darker, more muted than Briar Queen Chill.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Bright Slate Grey is noticeably darker, more muted than Briar Queen Chill.
The same difference applies the other way round: Briar Queen Chill is noticeably 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 Briar Queen Chill on the colour wheel See Bright Slate Grey on the colour wheel
All matches: Briar Queen Chill equivalents · Bright Slate Grey equivalents