ΔE 16.3, loose: different enough that you should pick on purpose. Pure Filth is a little darker, much more muted, cooler than Brethil Blush.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Pure Filth is a little darker, much more muted, cooler than Brethil Blush.
The same difference applies the other way round: Brethil Blush is a little lighter, much 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 Brethil Blush on the colour wheel See Pure Filth on the colour wheel
All matches: Brethil Blush equivalents · Pure Filth equivalents