ΔE 11.3, fair: the same colour family, but not a straight swap. Tarnished Steel is a little lighter, more muted than Canoptek Alloy.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Tarnished Steel is a little lighter, more muted than Canoptek Alloy.
The same difference applies the other way round: Canoptek Alloy 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 Canoptek Alloy on the colour wheel See Tarnished Steel on the colour wheel
All matches: Canoptek Alloy equivalents · Tarnished Steel equivalents