ΔE 29.3, loose: different enough that you should pick on purpose. Metallic Black is a little darker, much more muted than Emperor Gold.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Metallic Black is a little darker, much more muted than Emperor Gold.
The same difference applies the other way round: Emperor Gold is a little lighter, much 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 Emperor Gold on the colour wheel See Metallic Black on the colour wheel
All matches: Emperor Gold equivalents · Metallic Black equivalents