ΔE 11.7, fair: the same colour family, but not a straight swap. Steel Grey is a little lighter than Dark Ghost Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Steel Grey is a little lighter than Dark Ghost Gray.
The same difference applies the other way round: Dark Ghost Gray 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 Dark Ghost Gray on the colour wheel See Steel Grey on the colour wheel
All matches: Dark Ghost Gray equivalents · Steel Grey equivalents