ΔE 11.0, fair: the same colour family, but not a straight swap. Steel Grey is a little lighter, more saturated than Dark Olive.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Steel Grey is a little lighter, more saturated than Dark Olive.
The same difference applies the other way round: Dark Olive 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 Olive on the colour wheel See Steel Grey on the colour wheel
All matches: Dark Olive equivalents · Steel Grey equivalents