ΔE 14.5, fair: the same colour family, but not a straight swap. Iridescent Gold Deep (Fine) is noticeably lighter, warmer than Balthasar Gold. They are different kinds of paint: Citadel Balthasar Gold is a metallic and Golden Iridescent Gold Deep (Fine) is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Iridescent Gold Deep (Fine) is noticeably lighter, warmer than Balthasar Gold. They are different kinds of paint.
The same difference applies the other way round: Balthasar Gold is noticeably darker, cooler.
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 Balthasar Gold on the colour wheel See Iridescent Gold Deep (Fine) on the colour wheel
All matches: Balthasar Gold equivalents · Iridescent Gold Deep (Fine) equivalents