ΔE 24.0, loose: different enough that you should pick on purpose. Champagne Gold is a little lighter, much more saturated than Runefang Steel.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Champagne Gold is a little lighter, much more saturated than Runefang Steel.
The same difference applies the other way round: Runefang Steel is a little darker, much 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 Runefang Steel on the colour wheel See Champagne Gold on the colour wheel
All matches: Runefang Steel equivalents · Champagne Gold equivalents