ΔE 9.3, close: similar, with a visible difference side by side. Dirty Grey is a little lighter than Battle Dress Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Dirty Grey is a little lighter than Battle Dress Green.
The same difference applies the other way round: Battle Dress Green is a little darker.
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 Battle Dress Green on the colour wheel See Dirty Grey on the colour wheel
All matches: Battle Dress Green equivalents · Dirty Grey equivalents