ΔE 11.9, fair: the same colour family, but not a straight swap. Black Green RLM70 is a little lighter, more muted than Steel Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Black Green RLM70 is a little lighter, more muted than Steel Grey.
The same difference applies the other way round: Steel Grey is a little darker, more saturated.
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 Steel Grey on the colour wheel See Black Green RLM70 on the colour wheel
All matches: Steel Grey equivalents · Black Green RLM70 equivalents