ΔE 11.5, fair: the same colour family, but not a straight swap. Tarnished Brass is a little darker than Skullcrusher Brass.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Tarnished Brass is a little darker than Skullcrusher Brass.
The same difference applies the other way round: Skullcrusher Brass is a little lighter.
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 Skullcrusher Brass on the colour wheel See Tarnished Brass on the colour wheel
All matches: Skullcrusher Brass equivalents · Tarnished Brass equivalents