ΔE 13.4, fair: the same colour family, but not a straight swap. Rusty Metal is a little lighter, more muted, cooler than Old Gold.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Rusty Metal is a little lighter, more muted, cooler than Old Gold.
The same difference applies the other way round: Old Gold is a little darker, more saturated, warmer.
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 Old Gold on the colour wheel See Rusty Metal on the colour wheel
All matches: Old Gold equivalents · Rusty Metal equivalents