ΔE 10.9, fair: the same colour family, but not a straight swap. Gold Brown is a little darker, more muted than Bullion.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Gold Brown is a little darker, more muted than Bullion.
The same difference applies the other way round: Bullion is a little lighter, 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 Bullion on the colour wheel See Gold Brown on the colour wheel
All matches: Bullion equivalents · Gold Brown equivalents