Zamesi Desert vs Dark Yellow

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Dark Yellow is more muted, cooler than Zamesi Desert.

Can I use Dark Yellow instead of Zamesi Desert?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Dark Yellow is more muted, cooler than Zamesi Desert.

Can I use Zamesi Desert instead of Dark Yellow?

The same difference applies the other way round: Zamesi Desert is more saturated, 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.