Bright Gold vs Pucker

How close are they?

ΔE 20.2, loose: different enough that you should pick on purpose. Pucker is noticeably lighter, more saturated, cooler than Bright Gold.

Can I use Pucker instead of Bright Gold?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Pucker is noticeably lighter, more saturated, cooler than Bright Gold.

Can I use Bright Gold instead of Pucker?

The same difference applies the other way round: Bright Gold is noticeably darker, more muted, warmer.

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.