ΔE 12.8, fair: the same colour family, but not a straight swap. Beret Maroon is noticeably darker, more saturated, cooler than Vermin Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Beret Maroon is noticeably darker, more saturated, cooler than Vermin Brown.
The same difference applies the other way round: Vermin Brown is noticeably lighter, more muted, 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 Vermin Brown on the colour wheel See Beret Maroon on the colour wheel
All matches: Vermin Brown equivalents · Beret Maroon equivalents