Runefang Steel vs Hammered Copper

How close are they?

ΔE 9.2, close: similar, with a visible difference side by side. Hammered Copper is more saturated than Runefang Steel.

Can I use Hammered Copper instead of Runefang Steel?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Hammered Copper is more saturated than Runefang Steel.

Can I use Runefang Steel instead of Hammered Copper?

The same difference applies the other way round: Runefang Steel is 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.