Tainted Gold vs Heirloom Gold

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Heirloom Gold is noticeably lighter, more muted than Tainted Gold.

Can I use Heirloom Gold instead of Tainted Gold?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Heirloom Gold is noticeably lighter, more muted than Tainted Gold.

Can I use Tainted Gold instead of Heirloom Gold?

The same difference applies the other way round: Tainted Gold is noticeably darker, 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.