ΔE 11.6, fair: the same colour family, but not a straight swap. Red Brown is a little lighter, more muted, cooler than Beret Maroon.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Red Brown is a little lighter, more muted, cooler than Beret Maroon.
The same difference applies the other way round: Beret Maroon is a little darker, 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 Beret Maroon on the colour wheel See Red Brown on the colour wheel
All matches: Beret Maroon equivalents · Red Brown equivalents