ΔE 24.8, loose: different enough that you should pick on purpose. Imperial Gold is noticeably lighter, much more muted than Rich Gold.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Imperial Gold is noticeably lighter, much more muted than Rich Gold.
The same difference applies the other way round: Rich Gold is noticeably darker, 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 Rich Gold on the colour wheel See Imperial Gold on the colour wheel
All matches: Rich Gold equivalents · Imperial Gold equivalents