ΔE 12.2, fair: the same colour family, but not a straight swap. Cam. Middle Brown is a little lighter, more muted, cooler than WWI French Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Cam. Middle Brown is a little lighter, more muted, cooler than WWI French Brown.
The same difference applies the other way round: WWI French Brown 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 WWI French Brown on the colour wheel See Cam. Middle Brown on the colour wheel
All matches: WWI French Brown equivalents · Cam. Middle Brown equivalents