ΔE 19.8, loose: different enough that you should pick on purpose. Ivory is a little darker, much more muted than Arid Earth.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Ivory is a little darker, much more muted than Arid Earth.
The same difference applies the other way round: Arid Earth is a little lighter, much 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.
See Arid Earth on the colour wheel See Ivory on the colour wheel
All matches: Arid Earth equivalents · Ivory equivalents