ΔE 17.9, loose: different enough that you should pick on purpose. Glittering Loot is noticeably darker, much more saturated, warmer than Old Gold.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Glittering Loot is noticeably darker, much more saturated, warmer than Old Gold.
The same difference applies the other way round: Old Gold is noticeably lighter, much more muted, 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 Old Gold on the colour wheel See Glittering Loot on the colour wheel
All matches: Old Gold equivalents · Glittering Loot equivalents