ΔE 12.0, fair: the same colour family, but not a straight swap. Longbeard Grey is a little lighter, more muted than Desert Olive Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Longbeard Grey is a little lighter, more muted than Desert Olive Green.
The same difference applies the other way round: Desert Olive Green is a little darker, more saturated.
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 Desert Olive Green on the colour wheel See Longbeard Grey on the colour wheel
All matches: Desert Olive Green equivalents · Longbeard Grey equivalents