ΔE 9.1, close: similar, with a visible difference side by side. Natural Steel is a little lighter, more saturated than Metallic Black.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Natural Steel is a little lighter, more saturated than Metallic Black.
The same difference applies the other way round: Metallic Black 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 Metallic Black on the colour wheel See Natural Steel on the colour wheel
All matches: Metallic Black equivalents · Natural Steel equivalents