ΔE 14.9, fair: the same colour family, but not a straight swap. Fair Shadow is a little lighter, much more muted than Brethil Blush.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Fair Shadow is a little lighter, much more muted than Brethil Blush.
The same difference applies the other way round: Brethil Blush is a little darker, much 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 Brethil Blush on the colour wheel See Fair Shadow on the colour wheel
All matches: Brethil Blush equivalents · Fair Shadow equivalents