ΔE 6.5, close: similar, with a visible difference side by side. Steel Grey is more saturated, warmer than Light Ghost Gray.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Steel Grey is more saturated, warmer than Light Ghost Gray.
The same difference applies the other way round: Light Ghost Gray is more muted, cooler.
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 Light Ghost Gray on the colour wheel See Steel Grey on the colour wheel
All matches: Light Ghost Gray equivalents · Steel Grey equivalents