ΔE 10.3, fair: the same colour family, but not a straight swap. Dark Green RLM71 is a little darker, cooler than Drab Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Dark Green RLM71 is a little darker, cooler than Drab Brown.
The same difference applies the other way round: Drab Brown is a little lighter, 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 Drab Brown on the colour wheel See Dark Green RLM71 on the colour wheel
All matches: Drab Brown equivalents · Dark Green RLM71 equivalents