ΔE 8.5, close: similar, with a visible difference side by side. Khaki Green is a little lighter, more saturated than Dark Drab.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Khaki Green is a little lighter, more saturated than Dark Drab.
The same difference applies the other way round: Dark Drab is a little darker, more muted.
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 Dark Drab on the colour wheel See Khaki Green on the colour wheel
All matches: Dark Drab equivalents · Khaki Green equivalents