Gold Leaf vs Gold Brown

How close are they?

ΔE 21.6, loose: different enough that you should pick on purpose. Gold Brown is noticeably darker, much more muted, warmer than Gold Leaf.

Can I use Gold Brown instead of Gold Leaf?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Gold Brown is noticeably darker, much more muted, warmer than Gold Leaf.

Can I use Gold Leaf instead of Gold Brown?

The same difference applies the other way round: Gold Leaf is noticeably lighter, much more saturated, 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.