ΔE 16.9, loose: different enough that you should pick on purpose. Rucksack Tan is a little darker, more muted, cooler than Zamesi Desert.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Rucksack Tan is a little darker, more muted, cooler than Zamesi Desert.
The same difference applies the other way round: Zamesi Desert is a little lighter, 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.
See Zamesi Desert on the colour wheel See Rucksack Tan on the colour wheel
All matches: Zamesi Desert equivalents · Rucksack Tan equivalents